Baker Mayfield has the highest completion percentage by a quarterback in a game with 20+ completions versus the Giants, at 84.4 percent on December 20.

highest completion percentage in a game vs giants by quarterback with at least 20 completions
Interpreted as:
highest completion percentage in a regular-season game vs giants by quarterback with at least 20 completions
12/20/2020Mayfield12/16/2012Ryan11/27/1989Montana10/6/2019Cousins9/30/1990Aikman1/3/2010Favre9/13/2015Romo11/16/2003McNabb1/2/1994Aikman10/22/2018Ryan1/3/2016Bradford1/1/2012Romo10/4/2020Goff10/27/2019Stafford9/8/2019Prescott11/1/2015Brees9/19/2010Manning10/18/2009Brees1/2/2005Testaverde9/16/2007Favre12/29/2007Brady9/5/2012Romo12/1/1946Waterfield84.482.181.881.580.880.680.080.080.079.578.978.478.178.178.178.076.976.776.776.376.275.975.9
NAMEDATETMOPPPCTCMPATTYDSAVGTDTD%INTINT%SCKSCKYRATE
Baker MayfieldBaker Mayfield12/20/2020CLECLE@ NYG
@
84.427322979.326.300.0111126.2
Matt RyanMatt Ryan12/16/2012ATLATLvs. NYG
vs.
82.123282709.6310.700.015142.6
Joe MontanaJoe Montana11/27/1989SFSFvs. NYG
vs.
81.827332928.839.100.027133.8
Kirk CousinsKirk Cousins10/6/2019MINMIN@ NYG
@
81.5222730611.327.400.0327138.6
Troy AikmanTroy Aikman9/30/1990DALDAL@ NYG
@
80.821262339.013.813.800100.8
Brett FavreBrett Favre1/3/2010MINMINvs. NYG
vs.
80.6253131610.2412.900.000148.7
Tony RomoTony Romo9/13/2015DALDALvs. NYG
vs.
80.036453567.936.724.400103.3
Donovan McNabbDonovan McNabb11/16/2003PHIPHIvs. NYG
vs.
80.0243031410.526.700.000132.5
Troy AikmanTroy Aikman1/2/1994DALDAL@ NYG
@
80.024301806.013.300.0423102.8
Matt RyanMatt Ryan10/22/2018ATLATLvs. NYG
vs.
79.531393799.712.600.0323115.7
Sam BradfordSam Bradford1/3/2016PHIPHI@ NYG
@
78.930383208.425.312.615108.3
Tony RomoTony Romo1/1/2012DALDAL@ NYG
@
78.429372897.825.412.7638106.0
Jared GoffJared Goff10/4/2020LARLARvs. NYG
vs.
78.125322006.313.100.0218103.1
Matthew StaffordMatthew Stafford10/27/2019DETDETvs. NYG
vs.
78.1253234210.739.413.1426129.4
Dak PrescottDak Prescott9/8/2019DALDALvs. NYG
vs.
78.1253240512.7412.500.000158.3
Drew BreesDrew Brees11/1/2015NONOvs. NYG
vs.
78.0395050510.1714.024.000131.7
Peyton ManningPeyton Manning9/19/2010INDINDvs. NYG
vs.
76.920262559.8311.500.015145.5
Drew BreesDrew Brees10/18/2009NONOvs. NYG
vs.
76.7233036912.3413.300.000156.8
Vinny TestaverdeVinny Testaverde1/2/2005DALDAL@ NYG
@
76.723302317.713.300.0311109.2
Brett FavreBrett Favre9/16/2007GBGB@ NYG
@
76.329382867.537.912.611112.4
Tom BradyTom Brady12/29/2007NENE@ NYG
@
76.232423568.524.800.0110116.8
Tony RomoTony Romo9/5/2012DALDAL@ NYG
@
75.9222930710.6310.313.4217129.5
Bob WaterfieldBob Waterfield12/1/1946LALA@ NYG
@
75.9222931210.8310.313.4130.2
Ty DetmerTy Detmer12/1/1996PHIPHIvs. NYG
vs.
75.825332848.639.113.0213118.8
Len DawsonLen Dawson11/3/1974KCKCvs. NYG
vs.
75.825332387.226.113.0102.8
Results may be incomplete. StatMuse has complete game-level data for completion percentage and completions going back to the 1950 season.

See Trending NFL Searches