Frolow v. Wilson Sporting Goods Co.

United States Court of Appeals
for the Federal Circuit
__________________________

JACK L. FROLOW,
Plaintiff-Appellant,
v.
WILSON SPORTING GOODS CO.,
Defendant-Appellee.
__________________________

2012-1185
__________________________

Appeal from the United States District Court for the
District of New Jersey in No. 05-CV-4813, Judge Freda L.
Wolfson.
__________________________

Decided: March 15, 2013
__________________________

ARTHUR M. PESLAK, Gertber, Mandel & Peslak, LLC,
of Lakewood, New Jersey, argued for the plaintiff-
appellant. Of counsel was Manny D. Polotilow, Caesar,
Rivise, Bernstein, Cohen, of Philadelphia, Pennsylvania.

JEFFREY A. KEY, Key & Associates, of Chicago, Illi-
nois, argued for defendant-appellee.
__________________________

Before NEWMAN, CLEVENGER, and MOORE, Circuit Judges.
FROLOW v. WILSON SPORTING 2

Opinion for the court filed by Circuit Judge MOORE, in
which Circuit Judge CLEVENGER joins with additional
views, further additional views filed by Circuit Judge
MOORE, and concurring opinion filed by Circuit Judge
NEWMAN.
MOORE, Circuit Judge.
Jack L. Frolow appeals from the final judgment of the
U.S. District Court for the District of New Jersey in favor
of Wilson Sporting Goods Co. (Wilson). Among other
issues, Mr. Frolow challenges the district court’s entry of
summary judgment in favor of Wilson and the court’s
entry of judgment as a matter of law (JMOL) at the close
of Mr. Frolow’s case. Because the district court erred
when it granted summary judgment, we reverse and
remand for the reasons set forth below. We affirm the
district court’s judgment for all other issues raised on
appeal.
BACKGROUND
This case involves Wilson’s alleged breach of a License
Agreement. Under the Agreement, Wilson agreed to pay
Mr. Frolow royalties for “Licensed Article(s),” defined as
“tennis rackets which are covered by one or more unex-
pired or otherwise valid claims” of Mr. Frolow’s U.S.
Patent RE33,372 (’372 patent). Frolow v. Wilson Sporting
Goods Co., No. 3:05-CV-4813, 2008 WL 8134447, at *3
(D.N.J. Mar. 31, 2008) (First Summary Judgment Order).
Claim 20 is representative of the claims at issue, claiming
a tennis racket with specific properties:
20. A complete tennis racket having at
least a head portion and a handle
portion, said handle having a grip
portion suitably adapted for the
hand to grip, the end of the grip
3 FROLOW v. WILSON SPORTING

portion being located at the handle
portion end of the racket; said
head portion supporting a string
netting in a plane, said netting
having vertical and horizontal
strings . . . ;

said racket having a weight distribution
providing for the center of percus-
sion located at a distance Cp in
inches from the end of the grip
portion . . . ;

said racket having a weight distribution
providing for the moment of iner-
tia Ia in ounce-inches squared
about said longitudinal axis . . . ;

and the magnitude of Ia is greater than 80
ounce-inches squared . . . .
’372 patent col.14 l.37–col.15 l.2. After conducting an
audit, Mr. Frolow concluded that Wilson was not paying
royalties on all the Licensed Articles and filed suit alleg-
ing that Wilson breached the License Agreement and
infringed the ’372 patent. Due to an arbitration provision
in the Agreement, the court limited the breach of contract
case to determining which Wilson racket models were
Licensed Articles. Frolow v. Wilson Sporting Goods Co.,
No. 3:05-CV-4813, 2006 WL 891201, at *2–3 (D.N.J. Apr.
5, 2006). It also summarily dismissed Mr. Frolow’s patent
infringement claim. Id. at *4.
The parties litigated the breach of contract issue, dis-
puting whether forty-two racket models were Licensed
Articles. Wilson moved for summary judgment that the
accused racket models were not Licensed Articles, which
FROLOW v. WILSON SPORTING 4

the court granted in part. The court held that Wilson’s
test data showed that thirty-seven of the forty-two racket
models had a moment of inertia of eighty ounce-inches
squared or less and thus did not fall within the scope of
the asserted claims. First Summary Judgment Order,
2008 WL 8134447, at *16–20. 1 Mr. Frolow contested
Wilson’s test data and pointed to the fact that Wilson had
marked fourteen of the rackets with the ’372 patent
number, arguing that Wilson’s marking raised a genuine
issue of material fact. The court rejected Mr. Frolow’s
marking argument and concluded that Wilson’s marking
had “no bearing on whether literal or doctrine of equiva-
lents infringement has occurred.” Id. at *21. The court
also declined to find that Wilson’s marking prevented it
from challenging whether the accused racket models were
Licensed Articles. Id. at *22. Finally, for five of the
racket models at issue, the court determined that Mr.
Frolow raised a genuine issue of material fact that those
rackets were Licensed Articles and set the case for trial.
Id. at *16–17.
After the final pretrial conference, Mr. Frolow alleged
that 299 additional racket models were Licensed Articles.
Wilson moved for summary judgment, contending that
Mr. Frolow added the 299 racket models too late in the
case and that Mr. Frolow failed to adduce any evidence
that the 299 racket models were Licensed Articles. Wil-
son also produced an expert report that showed that 82 of
the 299 racket models had a moment of inertia of eighty
ounce-inches squared or less. Wilson did not, however,
proffer any evidence for the remaining 217 rackets.

1 The court also concluded that the doctrine of pros-
ecution history estoppel barred Mr. Frolow’s doctrine of
equivalents theory for the “greater than 80 ounce inches
squared” limitation. Id. at *17–20. We agree.
5 FROLOW v. WILSON SPORTING

Mr. Frolow, in a declaration, contested Wilson’s test
data for the 82 racket models and stated that Wilson had
been paying royalties on the 299 racket models. Wilson
contended that the payments were “inadvertent” and
were “based on the mistaken belief” that the models fell
within the ’372 patent claims. Reply Mem., at 9, Frolow
v. Wilson Sporting Goods Co., No. 3:05-CV-4813 (D.N.J.
July 26, 2010), ECF No. 120.
The district court granted Wilson’s motion for sum-
mary judgment, concluding that Mr. Frolow’s attempt to
add the 299 racket models was untimely and violated the
court’s prior orders. Frolow v. Wilson Sporting Goods Co.,
No. 3:05-CV-4813, 2010 WL 5150161, at *4–5 (D.N.J. Dec.
13, 2010) (Second Summary Judgment Order). In addi-
tion, the court concluded that summary judgment was
appropriate because Mr. Frolow failed to proffer any
evidence that the rackets fell within the scope of the ’372
patent claims. Id. at *5–6.
The parties then tried the issue of whether the five
remaining racket models were Licensed Articles. After
Mr. Frolow rested his case, the court entered JMOL that
the rackets were not Licensed Articles. The court con-
cluded that Mr. Frolow “adduced no testimony whatsoever
concerning the head, handle, grip or strings” in the ac-
cused tennis rackets as required by the asserted claims,
and that the parties did not stipulate to those facts.
Frolow v. Wilson Sporting Goods Co., No. 3:05-CV-4813,
2011 WL 2784093, at *3 (D.N.J. July 12, 2011) (JMOL
Order). The court also concluded that “none of the docu-
ments admitted as evidence during trial contain any
admissions regarding the head, handle, grip or strings” in
the accused tennis rackets. Id. The court declined to take
judicial notice of those facts because the string netting
configuration of tennis rackets was subject to reasonable
dispute. Id. at *4. The court denied Mr. Frolow’s motion
FROLOW v. WILSON SPORTING 6

for a new trial, and he appealed. 2 We have jurisdiction
under 28 U.S.C. § 1295(a)(1).
DISCUSSION
I. Standard of Review
We review the grant of summary judgment under the
law of the regional circuit, here the Third Circuit. Lexion
Med., LLC v. Northgate Techs., Inc., 641 F.3d 1352, 1358
(Fed. Cir. 2011). The Third Circuit reviews the grant of
summary judgment de novo. Nicini v. Morra, 212 F.3d
798, 805 (3d Cir. 2000) (en banc). Summary judgment is
appropriate if the movant “shows that there is no genuine
dispute as to any material fact and the movant is entitled
to judgment as a matter of law.” Fed. R. Civ. P. 56(a). At
the summary judgment stage, we credit all of the non-
movant’s evidence and draw all justifiable inferences in
his favor. Anderson v. Liberty Lobby, Inc., 477 U.S. 242,
255 (1986). Our function is not to “weigh the evidence
and determine the truth of the matter” but instead to
determine whether there is a genuine issue for trial. Id.
at 249.
We also review a district court’s grant of a motion for
JMOL under the law of the regional circuit. Union Car-
bide Chems. & Plastics Tech. Corp. v. Shell Oil Co., 308
F.3d 1167, 1185 (Fed. Cir. 2002). The Third Circuit
exercises plenary review of the grant of a motion for
JMOL. McGreevy v. Stroup, 413 F.3d 359, 363–64 (3d Cir.
2005). In the Third Circuit, “[a] motion for JMOL under
Federal Rule 50(a) should be granted only if, viewing the
evidence in the light most favorable to the nonmoving

2 Wilson argues that Mr. Frolow filed a limited no-
tice of appeal that narrowed the scope of the appeal to the
issues in the court’s JMOL order. We do not agree. Mr.
Frolow sufficiently identified the issues on appeal.
7 FROLOW v. WILSON SPORTING

party, there is no question of material fact for the jury
and any verdict other than the one directed would be
erroneous under the governing law.” Id. at 364 (internal
quotations omitted).
II. The Fourteen Marked Racket Models
Mr. Frolow argues that the district court erred in
granting Wilson’s first summary judgment motion be-
cause Wilson’s marking of fourteen racket models with
the ’372 patent number estopped it from arguing that
those models are not Licensed Articles. At a minimum,
argues Mr. Frolow, Wilson’s marking was sufficient to
raise a genuine issue of material fact as to whether the
fourteen racket models are Licensed Articles.
Wilson responds that Mr. Frolow failed to provide any
evidence to support estoppel. Wilson admits that it
marked the fourteen racket models, but contends that it
inadvertently mismarked them. Wilson also argues that
its expert report proved that the fourteen racket models
were not Licensed Articles because the rackets had a
moment of inertia of eighty ounce-inches squared or less.
Thus, argues Wilson, Mr. Frolow failed to raise a genuine
issue of material fact as to whether the marked rackets
are Licensed Articles.
A. Marking Estoppel
Under the doctrine of “marking estoppel” recognized
in some circuits, “a party that marks its product with a
patent number is estopped from asserting that the prod-
uct is not covered by the patent.” SmithKline Diagnostics,
Inc. v. Helena Labs. Corp., 859 F.2d 878, 890 n.9 (Fed.
Cir. 1989). We note that the Supreme Court has never
adopted or approved the doctrine. Mr. Frolow asks us to
adopt this doctrine and to hold that Wilson is estopped
from arguing that its fourteen marked rackets fall outside
FROLOW v. WILSON SPORTING 8

the ’372 patent claims. We decline to create a separate,
equitable doctrine unique to patent law, where Congress
has spoken and standard evidentiary practices provide
adequate remedy.
Congress enacted legislation, recently amended,
which provides a remedy for false marking. False Mark-
ing Statute, 35 U.S.C. § 292. Marking estoppel cases
explain that the rationale for the doctrine is to prevent
harm to the public which might be caused by mismarking.
See SmithKline, 859 F.2d at 890–91 (quoting Crane Co. v.
Aeroquip Corp., 364 F. Supp. 547, 560 (N.D. Ill. 1973)).
But Congress expressly addressed this exact harm and
crafted a remedy which it determined was appropriate to
remedy any harm to would-be competitors or innovators.
See Leahy-Smith America Invents Act, Pub. L. No. 112-
29, § 16(b)(2), 125 Stat. 284, 329 (2011) (amending 35
U.S.C. § 292(b)). Congress sought to protect the public
from false marking by providing a remedy in the form of
civil damages to persons “who ha[ve] suffered a competi-
tive injury as a result of” improper patent marking. Id. If
the mismarking was done “with the intent . . . of deceiving
the public” or some similar specific intent, the statute
provides for recovery under either the civil damages
provision (by an injured competitor) or the penalty provi-
sion (by the United States). 35 U.S.C. § 292(a). Equity
should not rush in where an adequate remedy at law
exists. It would be inconsistent with this legislation to
adopt a different and broader remedy for the same harm.
Although we do not endorse Mr. Frolow’s patent
marking doctrine, we do agree that the fact that Wilson
marked their products with his patent number is a fact
which supports his allegation that Wilson’s products fall
within the patent claims. The practice of marking a
product with a patent number is a form of extrajudicial
admission that the product falls within the patent claims.
9 FROLOW v. WILSON SPORTING

Extrajudicial admissions of fact are statements made by a
party outside the context of the litigation that are intro-
duced into evidence by that party’s opponent. E.g., Mar-
tha Graham School and Dance Foundation, Inc. v.
Martha Graham Ctr. of Contemporary Dance, Inc., 380
F.3d 624, 644 (2d Cir. 2004) (holding that the defendant’s
list of ballets “filmed and sold” constituted an admission
in copyright infringement action); Wright v. Farouk Sys.,
Inc., 701 F.3d 907, 910–11 (11th Cir. 2012) (holding that
statement by defendants’ Chairman that the defendant
was “in the process of re-formulating the product” in
response to defects was admissible in products liability
action). Generally, extrajudicial admissions of facts, such
as patent marking, are simply evidence that may be
countered by the party that made the admission. These
admissions are not “binding,” and “may be controverted or
explained by the party” that made the statement. See
30B Michael H. Graham, Federal Practice and Procedure
§ 7026 (interim ed. 2006) (citing 4 John Henry Wigmore,
Evidence in Trials at Common Law §§ 1058, 1059 (1972)).
The doctrine of marking estoppel would conflict with the
normal evidentiary treatment of these sorts of admis-
sions. We decline to adopt a special equitable doctrine for
the treatment of these “admissions.”
In this case, the district court erred when it held that
the defendant’s marking was irrelevant. Placing a patent
number on a product is an admission by the marking
party that the marked product falls within the scope of
the patent claims. The act of marking is akin to a corpo-
rate officer admitting in a letter or at a deposition that
the company’s product infringes a patent. A defendant, of
course, is free to introduce counter evidence or explana-
tion. Thus, the district court erred when it concluded that
Wilson’s marking had “no bearing on whether literal or
FROLOW v. WILSON SPORTING 10

doctrine of equivalents infringement has occurred.” First
Summary Judgment Order, 2008 WL 8134447, at *21.
Like any other type of extrajudicial admission, evi-
dence of marking is relevant evidence. And such an
admission, that the accused product falls within the
asserted claims, is certainly relevant on the issue of
infringement. Of course, whether a party’s marking, in
view of the record as a whole, raises a genuine issue of
material fact, will depend on the facts of each case.
B. Whether Wilson’s Marking Raises a Genuine Issue of
Material Fact
The district court granted Wilson’s motion for sum-
mary judgment that the marked racket models were not
Licensed Articles. At summary judgment, Wilson pro-
duced test data that showed that the racket models had a
moment of inertia of eighty ounce-inches squared or less.
Mr. Frolow submitted an expert declaration contesting
Wilson’s test data and provided evidence of Wilson’s
marking. He argued that Wilson’s continuous marking of
the fourteen racket models with the ’372 patent was
circumstantial evidence that those racket models are
Licensed Articles.
We conclude that in this case, where Mr. Frolow con-
tested whether the rackets fall within the scope of the
claims and provided evidence of marking, that summary
judgment is improper. To be clear, we are not holding
that the fact of marking alone is enough to survive sum-
mary judgment in every case. If a patentee admits that
the accused product does not infringe, evidence of mark-
ing will not raise a genuine issue of material fact. See
SmithKline, 859 F.2d at 890–91. Similarly, if it is beyond
dispute that the accused product was mis-marked, sum-
mary judgment will be appropriate. But evidence of
marking is circumstantial evidence that the marked
11 FROLOW v. WILSON SPORTING

product falls within the patent claims and can preclude
summary judgment in appropriate cases. Accordingly,
the district court erred when it concluded that Wilson’s
marking had “no bearing” on whether the rackets were
Licensed Articles. First Summary Judgment Order, 2008
WL 8134447, at *21.
It is hornbook law that a patentee may prove an issue
of fact “by either direct or circumstantial evidence.”
Liquid Dynamics Corp. v. Vaughan Co., 449 F.3d 1209,
1219 (Fed. Cir. 2006) (citing Moleculon Research Corp. v.
CBS, Inc., 793 F.2d 1261, 1272 (Fed. Cir. 1986)). Indeed,
“circumstantial evidence is not only sufficient, but may
also be more certain, satisfying and persuasive than
direct evidence.” Michalic v. Cleveland Tankers, Inc., 364
U.S. 325, 330 (1960). In reviewing the evidence, our task
is to discern whether “the record taken as a whole could
not lead a rational trier of fact to find for the non-moving
party.” Matsushita Elec. Indus. Co., Ltd. v. Zenith Radio
Corp., 475 U.S. 574, 587 (1986) (emphasis added).
The evidence in this case points in both directions.
Wilson’s expert report tends to show that its rackets are
not Licensed Articles and Mr. Frolow’s evidence of mark-
ing tends to show that those rackets are Licensed Articles.
It is the job of the fact-finder—not the court at summary
judgment—to weigh that evidence and render a decision.
Anderson, 477 U.S. at 255. We therefore reverse the
court’s grant of summary judgment and remand for
further proceedings.
III. The 299 Racket Models
Mr. Frolow argues that the court erred in granting
Wilson’s second motion for summary judgment on the 299
racket models. Before the district court, Wilson moved for
summary judgment that the 299 racket models were not
Licensed Articles. It argued that Mr. Frolow added the
FROLOW v. WILSON SPORTING 12

models too late in the case and failed to submit any evi-
dence that the 299 models were Licensed Articles. For 82
of the 299 models, Wilson produced an expert report that
concluded that those models had a moment of inertia of
eighty-ounce inches squared or less and were not Licensed
Articles. Wilson did not provide any data for the remain-
ing 217 racket models.
In response, Mr. Frolow submitted a declaration dis-
puting Wilson’s test data and stating that Wilson had
been paying royalties on the 299 racket models. 3 Wilson
admitted that it paid royalties for the racket models but
asserted that these payments were mistaken.
A. Whether Wilson’s Past Royalty Payments Raises a
Genuine Issue of Material Fact
We agree with Mr. Frolow that the district court erred
in granting summary judgment. Because the License
Agreement obligates Wilson to pay royalties based upon
its sales of Licensed Articles, Wilson’s history of paying
royalties on the 299 racket models is circumstantial
evidence that those models are Licensed Articles.
For 217 of the racket models, Wilson failed to intro-
duce any evidence that those racket models fall outside
the ’372 patent claims. Wilson admitted that it had been
paying royalties on the 217 rackets. Under these circum-
stances, it was improper to grant summary judgment.

3 Mr. Frolow also argues that Wilson should be es-
topped from denying that the 299 rackets models are
Licensed Articles because Wilson had been paying royal-
ties on those models. Licensing payments, like marking,
is circumstantial evidence in the form of an extrajudicial
admission. We decline, however, to create a new equita-
ble doctrine which would prevent a licensee from ever
arguing that its Licensed Article fell within the patent
claims.
13 FROLOW v. WILSON SPORTING

For 82 of the racket models, Wilson provided test data
that it argued established that the racket models were not
License Articles. Mr. Frolow disputed the accuracy of
Wilson’s data. He also provided evidence that Wilson had
been paying royalties on the 82 racket models. This
evidence, like Mr. Frolow’s marking evidence, constitutes
admissible circumstantial evidence that the rackets fell
within the terms of the patent claims. In light of this
competing evidence, we conclude that Mr. Frolow raised a
genuine issue of material fact and reverse the district
court’s grant of summary judgment.
This is not to say that evidence of past royalty pay-
ments will raise a genuine issue of material fact in every
case. For example, had Mr. Frolow admitted that Wil-
son’s test data for the 82 racket models was accurate, this
would be a different case and summary judgment would
be appropriate for 82 of the 299 racket models. There
may be other sets of facts which would warrant summary
judgment despite a history of licensing payments. But
evidence of past royalty payments is circumstantial
evidence that may preclude summary judgment in appro-
priate cases. And we concluded that the evidence is this
case raises a genuine issue of material fact.
B. The District Court’s Discretionary Power to Dismiss
299 Racket Models
The district court also based its summary judgment
on the fact that Mr. Frolow identified the racket models
too late in the proceedings. Second Summary Judgment
Order, 2010 WL 5150161, at *4–6. That was in error.
Excluding the racket models on the basis that Mr. Frolow
failed to timely identify them is certainly within a court’s
discretionary power. Such a decision would result in
dismissal of the claims, not a judgment on the merits that
the 299 racket models are not Licensed Articles. It is true
FROLOW v. WILSON SPORTING 14

that Mr. Frolow failed to identify the racket models in the
pretrial order, during discovery, in his expert reports, or
in connection with the first summary judgment motion.
And we leave it to the sound discretion of the district
court to determine whether the 299 racket models should
be included in this proceeding on remand. See Phx. Can.
Oil Co. v. Texaco, Inc., 842 F.2d 1466, 1475–75 (3d Cir.
1988). But we do conclude that Mr. Frolow has submitted
sufficient evidence to preclude a judgment on the merits
in this case as to those models.
IV. Burden of Proof on Remand
Neither party raises the issue of who will have the
burden of proof in the proceedings on remand. This may
be because “[p]erhaps the broadest and most accepted
idea is that the person who seeks court action should
justify the request, which means that the plaintiffs bear
the burdens on the elements in their claims.” Schaffer ex
rel. Schaffer v. Weast, 546 U.S. 49, 56 (2005) (quoting C.
Mueller & L. Kirkpatrick, Evidence § 3.1, p. 104 (3d ed.
2003)); see also Stockton East Water Dist. v. United States,
583 F.3d 1344, 1360 (Fed. Cir. 2009) (“Since this is a suit
for breach of contract, it is elementary that the plaintiff . .
. ha[s] the burden of persuasion on the issues of whether
there is a contract, and whether that contract was
breached . . . .”). Judge Newman’s concurrence, however,
contends that on remand the burden should shift to
Wilson to prove that its rackets are not Licensed Articles
because Wilson marked some rackets with the ’372 patent
number and historically paid royalties on other rackets.
This is incorrect. New Jersey law is clear that “[t]o
establish a breach of contract claim, a plaintiff has the
burden to show that the parties entered into a valid
contract, that the defendant failed to perform his obliga-
tions under the contract and that the plaintiff sustained
15 FROLOW v. WILSON SPORTING

damages as a result.” Murphy v. Implicito, 392 N.J.
Super. 245, 265 (App. Div. 2007); Litton Indus., Inc. v.
IMO Indus., Inc., 982 A.2d 420, 433 (N.J. 2009) (“[T]he
burden of proof was upon plaintiffs to establish that
defendants breached the contract.”). Likewise, “a breach
of contract will not be presumed.” Nolan v. Control Data
Corp., 243 N.J. Super. 420, 438 (App. Div. 1990).
The concurrence fails to cite any authority that a par-
ty’s extrajudicial admission shifts the burden of proof
from the plaintiff to the defendant. Indeed, all the au-
thority upon which the concurrence relies relates to
evidence a court may consider when interpreting a con-
tract, e.g., N.J. Stat. Ann. § 12A:2-208 cmt. n.1, or wheth-
er a party, based on its conduct, can waive its right to
enforce a contract, e.g., Westinghouse Credit Corp. v.
Shelton, 645 F.2d 869, 874 (10th Cir. 1981). Neither of
those issues is present in this case, and none of that
authority mentions, let alone suggests, that a defendant
has the burden to disprove breach. The issue is whether
Wilson’s marking and past royalty payments are evidence
that the goods in question are “Licensed Articles,” i.e.,
goods which fall within the patent claims. This evidence
does support Mr. Frolow. It does not, however, create
some sort of presumption which shifts the burden to
Wilson to disprove breach; it simply supports Mr. Frolow’s
breach of contract claim.
V. The Five Racket Models Contested at Trial
Lastly, Mr. Frolow argues that the district court erred
in entering JMOL at the close of his case. According to
Mr. Frolow, it was beyond dispute that Wilson’s five
racket models met the head, handle, grip, and string
netting limitations of the ’372 patent claims. Mr. Frolow
asserts that the only dispute between the parties was
whether Wilson’s rackets met the moment of inertia and
FROLOW v. WILSON SPORTING 16

center of percussion limitations, and, accordingly, Mr.
Frolow focused his testimony on those issues.
Wilson responds that the district court properly en-
tered JMOL at the close of Mr. Frolow’s case. Wilson
contends that Mr. Frolow bore the burden of proof at trial
and failed to introduce any evidence that the five disputed
rackets met the basic limitations of the ’372 patent
claims. Wilson specifically argues that Mr. Frolow failed
to prove that the five rackets have a head, handle, grip,
and string netting. Moreover, asserts Wilson, the court
correctly concluded that Wilson did not stipulate to those
facts and rightly declined to take judicial notice of them.
Wilson’s argument that the five tennis rackets lack a
head, handle, grip, or a string netting borders on frivo-
lous. While it is true that Mr. Frolow bore the burden to
prove that the five racket models were covered by an
asserted claim of the ’372 patent, we caution parties to
limit the scope of the disputed issues to facts that are
truly disputable. And on this record, we fail to see a good
faith basis upon which Wilson could have argued that its
tennis rackets lacked heads, handles, grips, or strings.
Wilson’s own product evaluation reports, introduced into
evidence, state that the rackets tested had a “head” and a
“handle,” and were “strung” and “gripped.” J.A. 2530–52.
Because the claims do not require a specific arrangement
for these basic racket elements, Wilson’s product evalua-
tion reports are substantial evidence that the five racket
models had a head portion, handle portion, grip portion
and strings. Moreover, those facts are not subject to
reasonable dispute—every tennis racket has a head,
handle, grip, and strings.
While the claim limitations regarding the head, han-
dle, and grip are general in nature (any head, handle or
grip would meet them), the string limitation is not. The
17 FROLOW v. WILSON SPORTING

claims require that the string netting have “vertical and
horizontal strings.” The district court is correct that Mr.
Frolow failed to introduce any evidence at trial that shows
that the five racket models met the “string netting having
horizontal and vertical strings” limitation. He did not
introduce any evidence that depicted the racket models or
described their respective string netting configurations.
He also testified that he had never seen the five racket
models or an image or visual representation of them.
JMOL Order, 2011 WL 2784093, at *4. In addition, his
attorney admitted that Wilson did not at any point stipu-
late that the five racket models had horizontal and verti-
cal strings. Tr. of Proceedings, at 58–60, Frolow v. Wilson
Sporting Goods Co., No. 3:05-CV-4813 (D.N.J. Aug. 16,
2011), ECF No. 151. And we cannot conclude that the
district court abused its discretion when it declined to
take judicial notice that all tennis rackets have horizontal
and vertical strings. Wilson represented, and Mr. Frolow
did not dispute, that some tennis rackets do not have
horizontal and vertical strings but instead have string
nettings with diagonal or fan-shaped string configura-
tions. JMOL Order, 2011 WL 2784093, at *4. According-
ly, we affirm the district court’s entry of JMOL as to the
five racket models contested at trial.
CONCLUSION
We have considered the parties’ remaining arguments
and conclude that they are without merit. For the forego-
ing reasons, the decision of the district court is
AFFIRMED-IN-PART, REVERSED-IN-PART, AND
REMANDED
COSTS
Costs to Plaintiff-Appellant.
 United States Court of Appeals
for the Federal Circuit
__________________________

JACK L. FROLOW,
Plaintiff-Appellant,
v.
WILSON SPORTING GOODS CO.,
Defendant-Appellee.
__________________________

2012-1185
__________________________

Appeal from the United States District Court for the
District of New Jersey in No. 05-CV-4813, Judge Freda L.
Wolfson.
__________________________

CLEVENGER, Circuit Judge, additional views.
I write to explain why this is an unusual case. In ear-
lier proceedings, Wilson brought a summary judgment of
non-infringement, seeking to show that the 14 racket
models which Wilson had marked with Frolow’s patent
number did not in fact meet the limitations of Frolow’s
patent. Because Licensed Articles are defined as goods
that infringe the patent, Wilson’s summary judgment of
non-infringement was intended to prove that the 14
racket models are not Licensed Articles.
In the summary judgment proceedings, Frolow unsuc-
cessfully sought to undermine Wilson’s evidence of non-
infringement. On appeal to this court, Frolow did not
FROLOW v. WILSON SPORTING 2

challenge the holding by the district court that the 14
racket models fail to meet the moment of inertia claim
limitation. Instead, Frolow argued that summary judg-
ment cannot lie where there is evidence of marking,
notwithstanding the fact that the moment of inertia
limitation is not found in the 14 racket models.
On remand, the district court must consider the evi-
dence of marking, because, as the court concludes, mark-
ing is at least some evidence that Wilson may have
thought that the rackets were covered by the patent.
However, not all evidence, otherwise relevant, is admissi-
ble at trial to the jury. Under Fed. R. Evid. 403, “[t]he
court may exclude relevant evidence if its probative value
is substantially outweighed by a danger of one or more of
the following: unfair prejudice, confusing the issues, [or]
misleading the jury….” Under the circumstances of this
case, where it has been established that the 14 racket
models do not satisfy the moment of inertia limitation, it
may well be that the limited probative value of Frolow’s
marking evidence is outweighed by the risk that Wilson
would be unfairly prejudiced by its admission, or that the
evidence would mislead or confuse the jury. Cf., e.g.,
LaserDynamics, Inc. v. Quanta Computer, Inc., 694 F.3d
51, 78 (Fed. Cir. 2012) (it was abuse of discretion under
Rule 403 to admit a settlement agreement having proba-
tive value that was “greatly outweighed by the risk of
unfair prejudice, confusion of the issues, and misleading
the jury.”)
The question of whether Frolow’s marking evidence
should be excluded under Rule 403 can be resolved on a
motion in limine, before a jury is empaneled and judicial
resources are expended at trial.
Because of the previous determination that the 14
racket models do not meet the moment of inertia limita-
3 FROLOW v. WILSON SPORTING

tion, this case is unlike other cases in which a defendant’s
admission that a product met asserted claims is balanced
against doubt as to whether the product in fact met the
limitations of the claim. In such circumstances, where
the jury must decide if the product meets the limitations
of the claim, there is less risk of unfair prejudice, confus-
ing the issues or misleading the jury associated with
admitting the defendant’s admission into evidence. See,
for example, Buckley v. Airshield Corp., 116 F. Supp. 2d
658, 669 (D. Md. 2000).
 United States Court of Appeals
for the Federal Circuit
__________________________

JACK L. FROLOW,
Plaintiff-Appellant,
v.
WILSON SPORTING GOODS CO.,
Defendant-Appellee.
__________________________

2012-1185
__________________________

Appeal from the United States District Court for the
District of New Jersey in No. 05-CV-4813, Judge Freda L.
Wolfson.
__________________________

MOORE, Circuit Judge, additional views.
I write in response to Judge Clevenger’s additional
views. As an initial matter, I agree completely that there
may well be circumstances when evidence of a defendant
having marked their product with a patent number could
be excluded pursuant to Federal Rule of Evidence 403.
For example, if it was admitted or established as a matter
of law that defendant’s marking was inadvertent, then
admission of the marking evidence would be “substantial-
ly outweighed by a danger or one or more of the following:
unfair prejudice, confusing the issues, [or] misleading the
jury.” Fed. R. Evid. 403. Alternatively, if the parties
agreed that an element of the claim was not present in
FROLOW v. WILSON SPORTING 2

the accused device, then marking evidence could be un-
fairly prejudicial.
I write separately because I do not agree with Judge
Clevenger’s claim that “Under the circumstances of this
case, where it has been established that the 14 racket
models do not satisfy the moment of inertia limitation, it
may well be that the limited probative value of Frolow’s
marking evidence is outweighed by the risk that Wilson
would be unfairly prejudiced by its admission.” In this
case, noninfringement was established in circumstances
where the judge refused to consider some evidence of
infringement—namely the marking. Mr. Frolow does not
admit or concede that the accused devices do not meet the
moment of inertia limitation. In fact, he introduced
evidence to the contrary. There is no motion in limine in
this case nor is it my job to prophesize on the outcome of a
motion that has never been filed. This circuit has cau-
tioned that “[e]vidence should be excluded until Rule 403
only sparingly” and that the balance under the rule
“should be struck in favor of admissibility.” Blancha v.
Raymark Indus., 972 F.2d 507, 516 (3d Cir. 1992). I leave
the application of this law to the district court judge.
 United States Court of Appeals
for the Federal Circuit
______________________

JACK L. FROLOW,
Plaintiff-Appellant,

v.

WILSON SPORTING GOODS CO.,
Defendants-Appellees.
______________________

2012-1185
______________________

Appeal from the United States District Court for
the District of New Jersey in No. 05-CV-4813, Judge
Freda L. Wolfson.
______________________

NEWMAN, Circuit Judge, concurring.
I agree that it is appropriate to remand to the district
court to resolve this dispute. I write separately because
the court appears to ignore, or trivialize, the power and
significance of Wilson’s consistent marking of 14 racket
models with Frolow’s patent number during the life of the
Frolow-Wilson License Agreement. Throughout the term
of the Agreement, Wilson’s position was that these
marked racket models were Licensed Articles, and by so
marking the rackets Wilson received the benefit of the
patent. This was not an inconsequential puff—it was an
announcement and admission that the rackets were
Licensed Articles under the contract.
2 FROLOW v. WILSON SPORTING
Wilson represented to Frolow, and the world at large,
that these rackets embodied Frolow’s technology and
Wilson would pay Frolow royalties. Only when Frolow
sought payment, did Wilson retreat. Frolow became
aware of Wilson’s renege only after Wilson exploited the
full value of Frolow’s patents as the exclusive licensee—so
that Frolow could not license other racket manufacturers.
At a minimum Wilson, not Frolow, bears the burden of
showing whether Wilson should now (after patent expira-
tion) be excused from paying for the benefit exclusively
licensed from Frolow.
On remand Wilson bears the burden of coming for-
ward with evidence adequate to show that it should not be
held to its own long-standing belief that the marked
rackets were Licensed Articles, a contract interpretation
on which both parties relied for the entire life of the
contract. I do not share my colleagues’ theory that the
parties’ view of their contract throughout its term is
merely “circumstantial evidence” of a royalty obligation
due.
DISCUSSION
The Restatement (Second) of Contracts § 202 (1981)
states that
Where an agreement involves repeated occasions
for performance by either party with knowledge of
the nature of the performance and opportunity for
objection to it by the other, any course of perfor-
mance accepted or acquiesced in without objection
is given great weight in the interpretation of the
agreement.
Under New Jersey law, a course of performance is
“the best indication” of what the parties meant by their
Agreement. N.J. Stat. Ann. §12A:2-208 cmt. n.1 (“The
parties themselves know best what they have meant by
their words of agreement and their action under that
 FROLOW v. WILSON SPORTING 3
agreement is the best indication of what that meaning
was.”); N.J. Stat. Ann. §12A:2-202 cmt. n.2 (“the course of
actual performance by the parties is considered the best
indication of what they intended the writing to mean.”);
see also N.J. Stat. Ann. §12A:2-208(3) (“course of perfor-
mance shall be relevant to show a waiver or modification
of any term inconsistent with such course of perfor-
mance.”); N.J. Stat. Ann. §12A:2-209(5) (waiver affecting
an executory portion of the contract may be retracted only
by “reasonable notification” and if not “unjust in view of a
material change of position in reliance on the waiver.”).
Wilson states that its marking of the 14 rackets was
“inadvertent.” The only record at trial and on appeal,
however, is that the rackets were intentionally marked on
Wilson’s belief that the rackets were “covered by” the
claims of the licensed Frolow ’372 patent. See Expert
Report of W. Severa 50, ECF No. 38-5 (“the mis-marking
occurred under the mistaken impression that the racquets
were covered by the claims of the ’372 patent.”). Wilson
has put forth no evidence of when its position changed.
Frolow had no notice of Wilson’s changed position until
after his audit. In such circumstances, a jury could de-
termine that Wilson’s unexplained and repeated marking
conduct constituted a waiver. See Westinghouse Credit
Corp. v. Shelton, 645 F.2d 869, 874 (10th Cir. 1981)
(remanding contract dispute under U.C.C. §2-209(5) for
factual determination of whether creditor’s course of
performance in accepting late payments constituted
waiver and, if so, whether the creditor reasonably retract-
ed the waiver “before taking [the debtor] to court.”).
Wilson’s post-expiration test data is relevant only if the
jury determines that Wilson should be permitted to
change its position after Frolow performed his obligations
under the contract.
The same reasoning applies to the racket models on
which Wilson had initially paid royalties. Indeed, in this
very case, the district court relied on Wilson’s payments
4 FROLOW v. WILSON SPORTING
on racket head covers as a course of performance estab-
lishing that racket head covers were Licensed Articles.
See Frolow v. Wilson Sporting Goods Co., 3:05-CV-04813-
FLW, 2008 WL 8134447, at *22 (D.N.J. Mar. 31, 2008)
(citing UCC §2–208(1)). The court explained that
to the extent that the course of performance under
the License Agreement shows that royalties were
paid to Frolow based on sales of racquet head co-
vers for racquet models that are Licensed Articles,
those head covers are themselves Licensed Arti-
cles; conversely, to the extent that the course of
performance under the License Agreement shows
that royalties were not paid to Frolow based on
sales of racquet head covers for racquet models
that are Licensed Articles, those head covers are
not Licensed Articles.
Id. Wilson did not appeal that ruling.
Frolow provided his technology to Wilson by exclusive
license and could not grant licenses to others. He cooper-
ated in Wilson’s lawsuits enforcing Frolow’s patents
against Wilson’s competitors, see Wilson Sporting Goods
Co. v. Head Sports, Inc., 98 C 1315, 1999 WL 89776 (N.D.
Ill. Feb. 9, 1999) (alleging that “three of Head’s most
popular tennis rackets infringe a patent held by Jack
Frolow and licensed to Wilson Sporting Goods Co.”);
Prince Sports Group, Inc. v. Wilson Sporting Goods Co.,
91 F.3d 167 (Fed. Cir. 1996) (“The baseline for this action
is a sublicense agreement . . . whereby Prince was to pay
Wilson royalties as its sublicensee under the Frolow
patents.”).
Wilson admitted significant failures in payments to
Frolow. On Frolow’s initial audit, Wilson admitted to
unpaid royalties in the amount of $694,044.35, and ten-
dered that amount to Frolow.
 FROLOW v. WILSON SPORTING 5
The majority opinion analogizes Wilson’s marking and
payment activities to “a corporate officer admitting in a
letter or at a deposition that the company’s product in-
fringes a patent,” Op. at 9, yet curiously does not put
these admissions in the contract context and holds that
the admissions do not relieve Frolow of the obligation of
proving infringement. The majority ignores that Wilson’s
“admissions” were made repeatedly, over a long period of
time, with commercial benefit to Wilson, and in a manner
consistent with accruing royalty obligations. A trier of
fact could certainly find that Wilson’s conduct was more
than a trivial “extrajudicial admission,” but was direct
evidence of obligations under the Agreement.
Finally, the majority’s reference to the recently
amended false marking statute, 35 U.S.C. §292, is inapt.
The false marking statute was a qui tam statute that
provided a bounty for persons who spotted products
marked with expired patents; it was amended to remedy
litigation abuse. There is absolutely no relationship to
the patent license and breach claims herein.
CONCLUSION
New Jersey statutes and precedent state the general
rule that a party to a contract who establishes a course of
performance of the contract, with no notice or objection,
may be bound by that performance. Wilson’s “admis-
sions” through marking and paying royalties on rackets
are of great evidentiary weight in contract law, and place
on Wilson the contract law burden of establishing that
some different interpretation should now be placed on this
expired contract. It is incorrect now to place on Frolow
the patent-law burden of proving infringement as if there
were no contract, no performance, no contrary interpreta-
tion and no reliance. Contract interpretation is a matter
of contract law. Although I concur in remanding to the
district court for further proceedings, I write separately to
emphasize that these are proceedings under a contract
6 FROLOW v. WILSON SPORTING
that has been fully performed and whose term has fully
run.