Gary Cuozzo and John Brodie are tied for the worst completion percentage by a quarterback in a game with 10+ passing attempts, at 0.0 percent.

(minimum 10 attempts) worst completion percentage ever in a game by a qb
Interpreted as:
(minimum 10 passing attempts) worst completion percentage ever in a regular-season game by a qb
11/7/1971Cuozzo10/23/1960Brodie10/3/1970Gault9/20/1998Leaf11/13/2005Pickett9/25/1988Kemp11/27/1977Hedberg12/12/1971Hargett12/1/1957McHan1/3/2010Palmer9/8/1985Wilson9/9/1984Kofler10/29/1972Sullivan10/20/1968Unitas11/2/1958Parilli11/12/1950Van Brocklin12/1/1985Bono9/21/1975Harris10/28/1973Hunter12/7/1958McHan12/5/1954Held11/20/1954Finks9/29/1974Namath0.00.06.36.77.78.38.38.38.39.19.19.19.19.19.19.110.010.010.010.010.010.011.1
NAMEDATETMOPPPCTATTCMPYDSAVGTDTD%INTINT%SCKSCKYRATE
Gary CuozzoGary Cuozzo11/7/1971MINMINvsSFSF0.010000.000.000.039.6
John BrodieJohn Brodie10/23/1960SFSF@GBGB0.013000.000.017.77.5
Don GaultDon Gault10/3/1970CLECLEvsPITPIT6.3161442.800.0212.50.0
Ryan LeafRyan Leaf9/20/1998SDSD@KCKC6.715140.300.0213.32230.0
Cody PickettCody Pickett11/13/2005SFSF@CHICHI7.7131282.200.017.7007.5
Jeff KempJeff Kemp9/25/1988SEASEAvsSFSF8.312160.500.0325.0180.0
Randy HedbergRandy Hedberg11/27/1977TBTBvsATLATL8.3121171.400.018.34.9
Edd HargettEdd Hargett12/12/1971NONOvsCLECLE8.3121100.800.000.039.6
Lamar McHanLamar McHan12/1/1957CHCCHC@CLECLE8.312190.800.018.34.9
Carson PalmerCarson Palmer1/3/2010CINCIN@NYJNYJ9.111100.000.019.1001.7
Dave WilsonDave Wilson9/8/1985NONOvsKCKC9.1222301.400.029.13141.7
Matt KoflerMatt Kofler9/9/1984BUFBUF@STLSTL9.111140.400.019.12181.7
Pat SullivanPat Sullivan10/29/1972ATLATLvsSFSF9.1111121.100.0218.20.0
Johnny UnitasJohnny Unitas10/20/1968BALBALvsCLECLE9.1111121.100.0327.30.0
Babe ParilliBabe Parilli11/2/1958GBGB@BALBAL9.111160.500.0327.30.0
Norm Van BrocklinNorm Van Brocklin11/12/1950LALA@GBGB9.1111282.519.119.132.0
Steve BonoSteve Bono12/1/1985MINMIN@PHIPHI10.010150.500.000.021339.6
James HarrisJames Harris9/21/1975LALA@DALDAL10.010150.500.0330.00.0
Scott HunterScott Hunter10/28/1973GBGB@DETDET10.0101-4-0.400.0110.00.0
Lamar McHanLamar McHan12/7/1958CHCCHC@CHBCHB10.010110.100.0220.00.0
Paul HeldPaul Held12/5/1954PITPIT@NYGNYG10.0101101.000.0330.00.0
Jim FinksJim Finks11/20/1954PITPITvsSFSF10.0101222.200.000.039.6
Joe NamathJoe Namath9/29/1974NYJNYJ@BUFBUF11.1182331.800.0316.70.0
Derek AndersonDerek Anderson10/11/2009CLECLE@BUFBUF11.8172231.400.015.91115.1
Jim ZornJim Zorn11/4/1979SEASEAvsLALA11.8172251.500.000.039.6
Results may be incomplete. StatMuse has complete game-level data for completion percentage and passing attempts going back to the 1950 season.

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