(Slip Opinion)              OCTOBER TERM, 2010                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

                 WALKER, WARDEN, ET AL. v. MARTIN

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                  THE NINTH CIRCUIT

 No. 09–996.       Argued November 29, 2010—Decided February 23, 2011
While most States set determinate time limits for collateral relief appli
 cations, California courts “appl[y] a general ‘reasonableness’ stan
 dard” to judge whether a habeas petition is timely filed, Carey v. Saf
 fold, 536 U. S. 214, 222. Under that standard, “a [habeas] petition
 should be filed as promptly as the circumstances allow . . . ,” In re
 Clark, 5 Cal. 4th 750, 765, n. 5, 855 P. 2d 729, 738, n. 5. Three deci
 sions, Clark, In re Robbins, 18 Cal. 4th 770, 959 P. 2d 311, and In re
 Gallego, 18 Cal. 4th 825, 959 P. 2d 290, describe California’s timeli
 ness requirement. A prisoner must seek habeas relief without “sub
 stantial delay,” e.g., Robbins, 18 Cal. 4th, at 780, 959 P. 3d, at 317, as
 “measured from the time the petitioner or counsel knew, or reasona
 bly should have known, of the information offered in support of the
 claim and the legal basis of the claim,” id., at 787, 959 P. 2d, at 322.
 All California courts have “original jurisdiction in habeas corpus pro
 ceedings.” Cal. Const., Art. VI, §10. Because a habeas petitioner
 may skip over the lower courts and file directly in the California Su
 preme Court, that court rules on a staggering number of habeas peti
 tions each year. A summary denial citing Clark and Robbins means
 that the petition is rejected as untimely. California courts, however,
 have discretion to bypass a timeliness issue and, instead, summarily
 reject the petition for want of merit.
    Respondent Martin was convicted of murder and robbery, and was
 sentenced to life in prison without parole. After the California Su
 preme Court denied Martin’s first state habeas petition, he filed a
 federal habeas petition. The District Court ordered a stay to permit
 Martin to return to state court to raise ineffective-assistance-of
 counsel claims he had not previously aired. Martin raised those
 claims in his second habeas petition in the California Supreme Court,
2                          WALKER v. MARTIN

                                  Syllabus

    but gave no reason for his failure to assert the additional claims until
    nearly five years after his sentence and conviction became final. The
    California Supreme Court denied the petition, citing Clark and Rob
    bins. Having exhausted his state-court remedies, Martin filed an
    amended federal habeas petition. The District Court dismissed his
    belatedly asserted claims as untimely under California law. The
    Ninth Circuit vacated that order and directed the District Court to
    determine the “adequacy” of the State’s time bar. Again rejecting
    Martin’s petition, the District Court found California’s bar an ade
    quate state ground for denying Martin’s new pleas. Concluding that
    the time bar was not firmly defined or consistently applied, the Ninth
    Circuit remanded for a determination of the merits of Martin’s
    claims.
Held: California’s timeliness requirement qualifies as an independent
 state ground adequate to bar habeas corpus relief in federal court.
 Pp. 7–13.
    (a) Absent showings of “cause” and “prejudice,” see Wainwright v.
 Sykes, 433 U. S. 72, 84–85, federal habeas relief will be unavailable
 when (1) “a state court [has] declined to address a prisoner’s federal
 claims because the prisoner had failed to meet a state procedural re
 quirement,” and (2) “the state judgment rests on independent and
 adequate state procedural grounds,” Coleman v. Thompson, 501 U. S.
 722, 729–730. P. 7.
    (b) A “rule can be ‘firmly established’ and ‘regularly followed,’ ” and
 therefore adequate, “even if the appropriate exercise of discretion
 may permit consideration of a federal claim in some cases but not
 others.” Beard v. Kindler, 558 U. S. ___, ___. California’s time rule,
 although discretionary, meets this “firmly established” criterion. The
 California Supreme Court framed the requirement in a trilogy of
 cases, instructing habeas petitioners to “alleg[e] with specificity” the
 absence of substantial delay, good cause for delay, or eligibility for
 one of four exceptions to the time bar. Gallego, 18 Cal. 4th, at 838,
 959 P. 2d, at 299. And California’s case law made it plain that Mar
 tin’s nearly five-year delay was “substantial.” See, e.g., id., at 829–
 831, 838, and n. 13, 959 P. 2d, at 293–294, 299, and n. 13. The Court
 finds unpersuasive Martin’s argument that the terms “reasonable
 time” period and “substantial delay” make California’s rule too vague
 to be regarded as “firmly established.” While indeterminate language
 is typical of discretionary rules, application of those rules in particu
 lar circumstances can supply the requisite clarity. Congressional
 statutes and this Court’s decisions have employed time limitations
 that are not stated in precise, numerical terms. For example, current
 federal habeas prescriptions limit the time for filing a petition to one
 year. The clock runs from “the date on which the [supporting] facts
                     Cite as: 562 U. S. ____ (2011)                     3

                                Syllabus

  . . . could have been discovered through . . . due diligence.” 28
  U. S. C. §2255(f)(4). Although “ ‘due diligence’ is an inexact measure
  of how much delay is too much,” Johnson v. United States, 544 U. S.
  295, 309, n. 7, “use of an imprecise standard is no justification for de
  priving [a rule’s] language of any meaning,” ibid. Nor is California’s
  time rule vulnerable on the ground that it is not regularly followed.
  Each year, the California State Supreme Court summarily denies
  hundreds of habeas petitions by citing Clark and Robbins. Contrary
  to Martin’s argument, California’s time bar is not infirm simply be
  cause a court may opt to bypass the Clark/Robbins assessment and
  summarily dismiss a petition on the merits, if that is the easier path.
  Nor should a discretionary rule be disregarded automatically upon a
  showing that outcomes under the rule vary from case to case. Discre
  tion enables a court to home in on case-specific considerations and to
  avoid the harsh results that may attend consistent application of an
  unyielding rule. A state ground may be found inadequate when a
  court has exercised its discretion in a surprising or unfair manner,
  but Martin makes no such contention here. Pp. 7–12.
      (c) This decision leaves unaltered the Court’s repeated recognition
  that federal courts must carefully examine state procedural require
  ments to ensure that they do not operate to discriminate against
  claims of federal rights. See, e.g., Brown v. Western R. Co. of Ala.,
  338 U. S. 294, 298–299. On the record here, however, there is no ba
  sis for concluding that California’s rule operates in such a discrimina
  tory manner. P. 13.
357 Fed. Appx. 793, reversed.

  GINSBURG, J., delivered the opinion for a unanimous Court.
                        Cite as: 562 U. S. ____ (2011)                              1

                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     preliminary print of the United States Reports. Readers are requested to
     notify the Reporter of Decisions, Supreme Court of the United States, Wash
     ington, D. C. 20543, of any typographical or other formal errors, in order
     that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 09–996
                                   _________________


  JAMES WALKER, WARDEN, ET AL., PETITIONERS
           v. CHARLES W. MARTIN
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                              [February 23, 2011] 


   JUSTICE GINSBURG delivered the opinion of the Court.
   This case concerns California’s time limitation on appli
cations for postconviction (habeas corpus) relief. The
question presented: Does California’s timeliness require
ment qualify as an independent state ground adequate to
bar habeas corpus relief in federal court?
   California does not employ fixed statutory deadlines to
determine the timeliness of a state prisoner’s petition for
habeas corpus. Instead, California directs petitioners to
file known claims “as promptly as the circumstances al
low.” In re Clark, 5 Cal. 4th 750, 765, n. 5, 855 P. 2d 729,
738, n. 5 (1993). Petitioners are further instructed to state
when they first learned of the asserted claims and to
explain why they did not seek postconviction relief sooner.
In re Robbins, 18 Cal. 4th 770, 780, 959 P. 2d 311, 317–
318 (1998). Claims substantially delayed without justifi
cation may be denied as untimely. Ibid.; Clark, 5 Cal. 4th,
at 765, n. 5, 855 P. 2d, at 738, n. 5.
   California courts signal that a habeas petition is denied
as untimely by citing the controlling decisions, i.e., Clark
and Robbins. A spare order denying a petition without
2                   WALKER v. MARTIN

                     Opinion of the Court

explanation or citation ordinarily ranks as a disposition on
the merits. Tr. of Oral Arg. 7; see Harrington v. Richter,
ante, at 9–10. California courts may elect to pretermit the
question whether a petition is timely and simply deny the
petition, thereby signaling that the petition lacks merit.
   Petitioner below, respondent here, Charles W. Martin,
presented the claims at issue—all alleging ineffective
assistance of counsel—in a habeas petition filed in the
California Supreme Court nearly five years after his con
viction became final. He stated no reason for the long
delay. Citing Clark and Robbins, the court denied Mar
tin’s petition. In turn, the U. S. District Court for the
Eastern District of California dismissed Martin’s federal
habeas petition raising the same ineffective assistance
claims. Denial of Martin’s state-court petition as un
timely, the District Court held, rested on an adequate and
independent state ground, i.e., Martin’s failure to seek
relief in state court “without substantial delay.” See
Robbins, 18 Cal. 4th, at 787, 959 P. 2d, at 322.
   The U. S. Court of Appeals for the Ninth Circuit re
versed the District Court’s decision. Contrasting the
precision of “fixed statutory deadlines” with California’s
proscription of “substantial delay,” the appeals court held
that California’s standard lacked the clarity and certainty
necessary to constitute an adequate state bar. 357 Fed.
Appx. 793, 794 (2009) (relying on Townsend v. Knowles,
562 F. 3d 1200 (CA9 2009)).
   In a recent decision, Beard v. Kindler, 558 U. S. ___
(2009), this Court clarified that a state procedural bar may
count as an adequate and independent ground for denying
a federal habeas petition even if the state court had dis
cretion to reach the merits despite the default. Guided by
that decision, we hold that California is not put to the
choice of imposing a specific deadline for habeas petitions
(which would almost certainly rule out Martin’s nearly
five-year delay) or preserving the flexibility of current
                      Cite as: 562 U. S. ____ (2011)                       3

                           Opinion of the Court

practice, “but only at the cost of undermining the finality
of state court judgments.” Id., at ___ (slip op., at 7). In so
ruling, we stress that Martin has not alleged that Califor
nia’s time bar, either by design or in operation, discrimi
nates against federal claims or claimants.
                               I

                               A

   While most States set determinate time limits for collat
eral relief applications, in California, neither statute nor
rule of court does so. Instead, California courts “appl[y] a
general ‘reasonableness’ standard” to judge whether a
habeas petition is timely filed. Carey v. Saffold, 536 U. S.
214, 222 (2002). The basic instruction provided by the
California Supreme Court is simply that “a [habeas] peti
tion should be filed as promptly as the circumstances
allow . . . .” Clark, 5 Cal. 4th, at 765, n. 5, 855 P. 2d, at
738, n. 5.
   Three leading decisions describe California’s timeliness
requirement: Robbins, Clark, and In re Gallego, 18 Cal.
4th 825, 959 P. 2d 290 (1998). A prisoner must seek ha
beas relief without “substantial delay,” Robbins, 18 Cal.
4th, at 780, 959 P. 2d, at 317; Gallego, 18 Cal. 4th, at 833,
959 P. 2d, at 296; Clark, 5 Cal. 4th, at 783, 855 P. 2d, at
750, as “measured from the time the petitioner or counsel
knew, or reasonably should have known, of the informa
tion offered in support of the claim and the legal basis for
the claim,” Robbins, 18 Cal. 4th, at 787, 959 P. 2d, at 322.
Petitioners in noncapital cases have “the burden of estab
lishing (i) absence of substantial delay, (ii) good cause for
the delay, or (iii) that the claim falls within an exception
to the bar of untimeliness.” Id., at 780, 959 P. 2d, at 317.1
——————
  1A    petition for habeas relief in a capital case is “presumed to be filed
without substantial delay if it is filed within 180 days after the final
due date for the filing of [an] appellant’s reply brief on the direct appeal
. . . .” California Supreme Court Policies Regarding Cases Arising From
4                       WALKER v. MARTIN

                         Opinion of the Court

   California’s collateral review regime differs from that of
other States in a second notable respect: All California
courts “have original jurisdiction in habeas corpus pro
ceedings,” Cal. Const., Art. VI, §10, thus “no appeal lies
from the denial of a petition for writ of habeas corpus,”
Clark, 5 Cal. 4th, at 767, n. 7, 855 P. 2d, at 740, n. 7. “[A]
prisoner whose petition has been denied by the superior
court can obtain review of his claims only by the filing of a
new petition in the Court of Appeal.” Ibid. The new
petition, however, must be confined to claims raised in the
initial petition. See In re Martinez, 46 Cal. 4th 945, 956,
209 P. 3d 908, 915 (2009).
   Because a habeas petitioner may skip over the lower
courts and file directly in the California Supreme Court,
In re Kler, 188 Cal. App. 4th 1399, 1403, 115 Cal. Rptr. 3d
889, 891–892 (2010), that court rules on a staggering
number of habeas petitions each year.2 The court issues
generally unelaborated “summary denials” of petitions
that “d[o] not state a prima facie case for relief” or that
contain “claims [that] are all procedurally barred.” People
v. Romero, 8 Cal. 4th 728, 737, 883 P. 2d 388, 391 (1994)
(internal quotation marks omitted). A summary denial
citing Clark and Robbins means that the petition is re
jected as untimely. See, e.g., Brief for Habeas Corpus
Resource Center as Amicus Curiae 20, and n. 23. Califor
nia courts have discretion, however, to bypass a timeliness
issue and, instead, summarily reject the petition for want

——————
Judgments of Death, Policy 3, Standard 1–1.1 (2010).
  2 In fiscal year 2008–2009, the California Supreme Court issued dis

positions in 3,258 original habeas actions. Judicial Council of Califor
nia, 2010 Court Statistics Report, Statewide Caseload Trends, 1999–
2000 Through 2008–2009, p. 6, http://www.courtinfo.ca.gov/reference/
documents/csr2010.pdf (as visited Feb. 15, 2011, and in Clerk of Court’s
case file). During a similar time period, a total of 2,210 habeas cases
were on this Court’s docket. See October Term 2008 Filings by Case
Type (available in Clerk of Court’s case file).
                      Cite as: 562 U. S. ____ (2011)                     5

                          Opinion of the Court

of merit. See Robbins, 18 Cal. 4th, at 778, n. 1, 959 P. 2d,
at 316, n. 1. See also Saffold, 536 U. S., at 225–226.
                                B
   In December 1986, Charles Martin participated in a
robbery and murder in California. Martin fled the State,
but eight years later he was extradited to California to
stand trial. Convicted in state court of murder and rob
bery, Martin was sentenced to life in prison without the
possibility of parole. In 1997, the California Court of
Appeal affirmed his conviction and sentence, and the
California Supreme Court denied review.
   Martin initiated his first round of state habeas proceed
ings in 1998, and the next year, the California Supreme
Court denied his petition. He then filed a habeas petition
in the appropriate U. S. District Court. Finding that
Martin’s federal petition included ineffective-assistance-of
counsel claims he had not aired in state court, the District
Court stayed the federal proceedings pending Martin’s
return to state court to exhaust his remedies there.3
   In March 2002, Martin filed his second habeas petition
in the California Supreme Court, raising the federal in
effective assistance claims his earlier filing omitted. He
gave no reason for his failure to assert the additional
claims until nearly five years after his sentence and con
viction became final. Tr. of Oral Arg. 36, 39. In Septem
ber 2002, the California Supreme Court denied Martin’s
petition in an order typical of that court’s summary dispo
sitions for failure to file “as promptly as the circumstances

——————
  3 Rather than dismiss a petition containing both exhausted and un

exhausted claims, “a district court might stay the petition and hold it in
abeyance while the petitioner returns to state court to exhaust his
previously unexhausted claims. Once the petitioner exhausts his state
remedies, the district court will lift the stay and allow the petitioner to
proceed in federal court.” Rhines v. Weber, 544 U. S. 269, 275–276
(2005).
6                    WALKER v. MARTIN

                     Opinion of the Court

allow.” Clark, 5 Cal. 4th, at 765, n. 5, 855 P. 2d, at 738,
n. 5. The order read in its entirety: “Petition for writ of
habeas corpus is DENIED. (See In re Clark (1993) 5 Cal.
4th 750, In re Robbins (1998) 18 Cal. 4th 770, 780.).” See
App. to Pet. for Cert. 60.
  Having exhausted state postconviction remedies, Martin
returned to federal court and filed an amended petition.
Based upon the California Supreme Court’s time-bar
disposition, the District Court dismissed Martin’s belat
edly asserted claims as procedurally precluded. Id., at 27,
57. The Ninth Circuit vacated the dismissal order and
remanded the case, directing the District Court to deter
mine the “adequacy” of the State’s time bar. Martin v.
Hubbard, 192 Fed. Appx. 616, 618 (2006). The District
Court again rejected Martin’s petition, stating that “[t]he
California timeliness bar as set forth in . . . Clark/Robbins
is clearly defined, well established and consistently ap
plied.” App. to Pet. for Cert. 4.
  The Ninth Circuit again disagreed. Controlled by its
prior decision in Townsend, 562 F. 3d, at 1207–1208, the
Court of Appeals held that California’s time bar “has yet
to be firmly defined” and was not shown by the State to be
“consistently applied.” 357 Fed. Appx., at 794. The re
mand order directed the District Court to determine the
merits of the claims Martin asserted in his second petition
to the California Supreme Court.
  We granted certiorari, 561 U. S. ___ (2010), to determine
the “adequacy” of California’s practice under which a
prisoner may be barred from collaterally attacking his
conviction when he has “substantially delayed” filing his
habeas petition. Martin does not here dispute that the
time limitation is an “independent” state ground. See
Brief in Opposition 5–6. See also Bennett v. Mueller, 322
F. 3d 573, 582–583 (CA9 2003). Nor does he contend that
he established “cause” and “prejudice,” i.e., cause for the
delay in asserting his claims and actual prejudice result
                  Cite as: 562 U. S. ____ (2011)             7

                      Opinion of the Court

ing from the State’s alleged violation of his constitutional
rights. See Wainwright v. Sykes, 433 U. S. 72, 87–91
(1977).
                               II 

                               A

   “A federal habeas court will not review a claim rejected
by a state court ‘if the decision of [the state] court rests on
a state law ground that is independent of the federal
question and adequate to support the judgment.’ ” Kind
ler, 558 U. S., at ___ (slip op., at 1) (quoting Coleman v.
Thompson, 501 U. S. 722, 729 (1991)). The state-law
ground may be a substantive rule dispositive of the case,
or a procedural barrier to adjudication of the claim on the
merits. See Sykes, 433 U. S., at 81–82, 90.
   Ordinarily, a state prisoner seeking federal habeas relief
must first “exhaus[t] the remedies available in the courts
of the State,” 28 U. S. C. §2254(b)(1)(A), thereby affording
those courts “the first opportunity to address and correct
alleged violations of [the] prisoner’s federal rights,” Cole
man, 501 U. S., at 731. The adequate and independent
state ground doctrine furthers that objective, for without
it, “habeas petitioners would be able to avoid the exhaus
tion requirement by defaulting their federal claims in
state court.” Id., at 732. Accordingly, absent showings of
“cause” and “prejudice,” see Sykes, 433 U. S., at 84–85,
federal habeas relief will be unavailable when (1) “a state
court [has] declined to address a prisoner’s federal claims
because the prisoner had failed to meet a state procedural
requirement,” and (2) “the state judgment rests on inde
pendent and adequate state procedural grounds.” Cole
man, 501 U. S., at 729–730.
                            B
  To qualify as an “adequate” procedural ground, a state
rule must be “firmly established and regularly followed. ”
8                        WALKER v. MARTIN

                          Opinion of the Court

Kindler, 558 U. S., at ___ (slip op., at 7) (internal quotation
marks omitted).4 “[A] discretionary state procedural rule,”
we held in Kindler, “can serve as an adequate ground to
bar federal habeas review.” Ibid. A “rule can be ‘firmly
established’ and ‘regularly followed,’ ” Kindler observed,
“even if the appropriate exercise of discretion may permit
consideration of a federal claim in some cases but not
others.” Ibid.
   California’s time rule, although discretionary, meets the
“firmly established” criterion, as Kindler comprehended
that requirement. The California Supreme Court, as
earlier noted, framed the timeliness requirement for ha
beas petitioners in a trilogy of cases. See supra, at 3.
Those decisions instruct habeas petitioners to “alleg[e]
with specificity” the absence of substantial delay, good
cause for delay, or eligibility for one of four exceptions to
the time bar. Gallego, 18 Cal. 4th, at 838, 959 P. 2d, at
299; see Robbins, 18 Cal. 4th, at 780, 959 P. 2d, at 317.5
——————
    4 Wehave also recognized a “limited category” of “exceptional cases in
which exorbitant application of a generally sound rule renders the state
ground inadequate to stop consideration of a federal question.” Lee v.
Kemna, 534 U. S. 362, 376 (2002). In Lee, for example, the defendant
unsuccessfully moved for a continuance when, for reasons unknown to
him, his alibi witnesses left the courthouse the day they were scheduled
to testify. This Court held inadequate to bar federal review a state
court’s persnickety application of a rule detailing formal requirements
for continuance motions. The defendant had substantially complied
with the rule’s key requirement and flawless compliance would have
been unavailing given the trial court’s reason for denying the motion.
See id., at 381–382. Martin does not suggest that the application of
California’s timeliness rule in his case falls within the exceptional
category Lee described and illustrated. See Brief for Respondent 28, 29,
54.
   5 An untimely petition “will be entertained on the merits if the peti

tioner demonstrates (i) that error of constitutional magnitude led to a
trial that was so fundamentally unfair that absent the error no reason
able judge or jury would have convicted the petitioner; (ii) that the
petitioner is actually innocent of the crime or crimes of which he or she
was convicted; (iii) that the death penalty was imposed by a sentencing
                     Cite as: 562 U. S. ____ (2011)                     9

                          Opinion of the Court

And California’s case law made it altogether plain that
Martin’s delay of nearly five years ranked as “substantial.”
See Gallego, 18 Cal. 4th, at 829–831, 838, and n. 13, 959
P. 2d, at 293–294, 299, and n. 13 (delay of four years
barred claim); In re Tsaturyan, No. B156012, 2002 WL
1614107, *3 (Cal. App., July 23, 2002) (delay of 16 months
barred claim). See also In re Miller, No. B186447, 2006
WL 1980385, *2–3 (Cal. App., July 17, 2006) (delay of two
years and six months barred claim).
   Martin nevertheless urges that California’s rule is too
vague to be regarded as “firmly established.” “[R]eason
able time” period and “substantial delay,” he maintains,
are “meaningless terms.” Brief for Respondent 48 (inter
nal quotation marks omitted). We disagree. Indetermi
nate language is typical of discretionary rules. Applica
tion of those rules in particular circumstances, however,
can supply the requisite clarity.
   Congressional statutes and this Court’s decisions, we
note, have employed time limitations that are not stated
in precise, numerical terms. Former Federal Habeas
Corpus Rule 9(a), for example, set no fixed time limit on
submission of habeas petitions. The Rule permitted dis
missal of a state prisoner’s petition when it appeared that
delay in commencing litigation “prejudiced [the State] in
its ability to respond.” 28 U. S. C. §2254 Rule 9(a) (1994
ed.). To stave off dismissal, the petitioner had to show
that he could not earlier have known, “by the exercise of
reasonable diligence,” the grounds on which he based the
petition. Ibid. In Rhines v. Weber, 544 U. S. 269 (2005),
we instructed district courts, when employing stay and
abeyance procedure, see supra, at 5, n. 3, to “place reason
——————
authority that had such a grossly misleading profile of the petitioner
before it that, absent the trial error or omission, no reasonable judge or
jury would have imposed a sentence of death; or (iv) that the petitioner
was convicted or sentenced under an invalid statute.” In re Robbins, 18
Cal. 4th 770, 780–781, 959 P. 2d 311, 318 (1998).
10                      WALKER v. MARTIN

                         Opinion of the Court

able time limits on a petitioner’s trip to state court and
back.” 544 U. S., at 278.
   Current federal habeas prescriptions limit the time for
filing a petition to one year. The clock runs from “the date
on which the [supporting] facts . . . could have been dis
covered through the exercise of due diligence.” 28 U. S. C.
§2255(f)(4) (2006 ed., Supp. III) (applicable to federal
prisoners); see §2244(d)(1)(D) (2006 ed.) (similar provision
applicable to state prisoners). “[D]ue diligence,” we have
observed, “ is an inexact measure of how much delay is too
much.” Johnson v. United States, 544 U. S. 295, 309, n. 7
(2005) (internal quotation marks omitted). But “use of an
imprecise standard,” we immediately added, “is no justifi
cation for depriving [a rule’s] language of any meaning.”
Ibid. “[I]t would seem particularly strange to disregard
state procedural rules that are substantially similar to
those to which we give full force in our own courts.” Kind-
ler, 558 U. S., at __ (slip op., at 8).
   Nor is California’s time rule vulnerable on the ground
that it is not regularly followed. Each year, the California
Supreme Court summarily denies hundreds of habeas
petitions by citing Clark and Robbins. Brief for Appellant
in No. 08–15752 (CA9), pp. 31–32. On the same day the
court denied Martin’s petition, it issued 21 other
Clark/Robbins summary denials. See Brief for Habeas
Corpus Resource Center as Amicus Curiae 20. In rea
soned opinions, too, California courts regularly invoke
Clark, Robbins, and Gallego to determine whether a ha
beas petition is time barred.6
   Martin argued below that California’s time bar is not
regularly followed in this sense: Use of summary denials
——————
  6 See, e.g., In re Sanders, 21 Cal. 4th 697, 703, 981 P. 2d 1038, 1042

(1999); In re Hamilton, 20 Cal. 4th 273, 283, n. 5, 975 P. 2d 600, 605,
n. 5 (1999); In re Watson, 104 Cal. Rptr. 3d 403, 407 (App. 2010) (offi
cially depublished); In re Nunez, 173 Cal. App. 4th 709, 723, 93 Cal.
Rptr. 3d 242, 252 (2009).
                      Cite as: 562 U. S. ____ (2011)                    11

                          Opinion of the Court

makes it “impossible to tell” why the California Supreme
Court “decides some delayed petitions on the merits and
rejects others as untimely.” Brief for Appellant in No. 08–
15752 (CA9), pp. 37–38. We see no reason to reject Cali
fornia’s time bar simply because a court may opt to bypass
the Clark/Robbins assessment and summarily dismiss a
petition on the merits, if that is the easier path. See, e.g.,
Strickland v. Washington, 466 U. S. 668, 697 (1984) (“[A]
court need not determine whether counsel’s performance
was deficient . . . [i]f it is easier to dispose of an ineffec
tiveness claim on the ground of lack of sufficient prejudice
. . . .”); cf. Ruhrgas AG v. Marathon Oil Co., 526 U. S. 574,
585 (1999) (“It is hardly novel for a federal court to choose
among threshold grounds for denying audience to a case
on the merits.”).
    The Ninth Circuit concluded that California’s time bar
is not consistently applied because outcomes under the
rule vary from case to case. See 357 Fed. Appx., at 794.
For example, in People v. Fairbanks, No. C047810, 2006
WL 950267, *2–*3 (Cal. App., Apr. 11, 2006), a one-year
delay was found substantial, while in In re Little, No.
D047468, 2008 WL 142832, *4, n. 6 (Cal. App., Jan. 16,
2008), a delay of 14 months was determined to be
insubstantial.
    A discretionary rule ought not be disregarded automati
cally upon a showing of seeming inconsistencies.7 Discre
——————
  7 Closerinspection may reveal that “seeming ‘inconsistencie[s]’ . . . are
not necessarily . . . arbitrar[y] or irrationa[l].” Thornburgh v. Abbott,
490 U. S. 401, 417, n. 15 (1989). Fairbanks and Little are illustrative.
In Fairbanks, the court found that petitioner did not act diligently
when she waited to withdraw her guilty plea until one year after
learning that revocation of her driver’s license was irreversible. 2006
WL 950267, *2–*3. In Little, a pro se prisoner claimed that his trial
counsel should have raised a posttraumatic stress disorder defense.
Although the filing delay was 14 months, the court entertained it on
the merits. 2008 WL 142832, *4, *14. Given the discrete context in
which each case arose, the two decisions present no square conflict.
12                        WALKER v. MARTIN

                          Opinion of the Court

tion enables a court to home in on case-specific considera
tions and to avoid the harsh results that sometimes
attend consistent application of an unyielding rule. See
Prihoda v. McCaughtry, 910 F. 2d 1379, 1385 (CA7 1990)
(“Uncertainty is not enough to disqualify a state’s
procedural ground as one ‘adequate’ under federal law. If
it were, states would be induced to make their rules
draconian . . . .”).
   A state ground, no doubt, may be found inadequate
when “discretion has been exercised to impose novel and
unforeseeable requirements without fair or substantial
support in prior state law . . . .” 16B C. Wright, A. Miller,
& E. Cooper, Federal Practice and Procedure §4026, p. 386
(2d ed. 1996) (hereinafter Wright & Miller); see Prihoda,
910 F. 2d, at 1383 (state ground “applied infrequently,
unexpectedly, or freakishly” may “discriminat[e] against
the federal rights asserted” and therefore rank as “inade
quate”). Martin does not contend, however, that in his
case, the California Supreme Court exercised its discretion
in a surprising or unfair manner.
   “[S]ound procedure often requires discretion to exact or
excuse compliance with strict rules,” 16B Wright & Miller
§4028, p. 403, and we have no cause to discourage stan
dards allowing courts to exercise such discretion. As this
Court observed in Kindler, if forced to choose between
mandatory rules certain to be found “adequate,” or more
supple prescriptions that federal courts may disregard as
“inadequate,” “many States [might] opt for mandatory
rules to avoid the high costs that come with plenary fed
eral review.” 558 U. S., at ___ (slip op., at 7). “Th[at]
result would be particularly unfortunate for [habeas peti
tioners], who would lose the opportunity to argue that a
procedural default should be excused through the exercise
of judicial discretion.” Id., at ___ (slip op., at 8).8
——————
 8 See   also 16B Wright & Miller §4026, pp. 385–386 (“Precisely defined
                     Cite as: 562 U. S. ____ (2011) 
                 13

                         Opinion of the Court 


                              C

    Today’s decision, trained on California’s timeliness rule
for habeas petitions, leaves unaltered this Court’s re
peated recognition that federal courts must carefully
examine state procedural requirements to ensure that
they do not operate to discriminate against claims of
federal rights. See Brown v. Western R. Co. of Ala., 338
U. S. 294, 298–299 (1949); Davis v. Wechsler, 263 U. S. 22,
24–25 (1923); 16B Wright & Miller §4026, p. 386 (noting
“risk that discretionary procedural sanctions may be
invoked more harshly against disfavored federal rights,
. . . deny[ing] [litigants] a fair opportunity to present
federal claims”). See also Kindler, 558 U. S., at ___
(KENNEDY, J., concurring) (slip op., at 3) (a state proce
dural ground would be inadequate if the challenger shows
a “purpose or pattern to evade constitutional guarantees”).
On the record before us, however, there is no basis for
concluding that California’s timeliness rule operates to the
particular disadvantage of petitioners asserting federal
rights.
                         *    *    *
  For the reasons stated, we find no inadequacy in Cali
fornia’s timeliness rule generally or as applied in Martin’s
case. The judgment of the United States Court of Appeals
for the Ninth Circuit is therefore
                                                   Reversed.




—————— 

rules cannot take account of the gravity of a procedural failure, the

strength of the excuses offered, or the importance of the procedural and 

substantive consequences of excusing or punishing the failure.”). 

