To me the 2014 and 2016 AFCCG weren't clutch performances rather just great games. The 2014 AFC Divisional game, SB 49 and SB 51 weren't exactly great full game performances but they were a clutch as I've ever seen.
This is the definition of clutch found in wiki.
Clutch (sports) - Wikipedia
Clutch performance in sports is the phenomenon of athletes under pressure, often in the last minutes of a game, to summon strength, concentration and whatever else necessary to succeed, to perform well, and perhaps change the outcome of the game. It occurs in basketball, hockey, football, other sports and
esports. The opposite is
"choking": failing to perform as needed, when under pressure.
But I do agree with you in that something is missing from his criteria. Maybe he needs to add a choking element because that would at least change where Manning is ranked.
Manning has had 45 comebacks and 56 game winning drives which is 6 more of each than Brady but I would never consider Manning anywhere near as clutch as TB.
I wondered if the criteria failed to penalize for choke performances so I looked up pick sixes and found this article from 2013.
Most Pick Sixes Thrown in NFL History
Tom Brady ranked 90th with 8 at the time.
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Most in one season:
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