I have a few criticisms of this article.
First, I don't understand the criteria for close games; "Record in games decided by 8 points or less." There are games when teams had no chance of winning but ended up scoring more to make it seem close in the box score. Conversely, there are games stuck in a stalemate until one team scores a lot of points late in the fourth quarter. The former would qualify even though there was no "crunch time" while the latter wouldn't qualify even though there was indeed "crunch time."
Second, and this is in respect to the criteria for close games again, the offense--and therefore the quarterback--doesn't have 100% influence on the outcome of the game. More interesting would be an analysis of an offense's last possession during which the offense had a chance to tie or take the lead. There were a few times I can vaguely remember Rodgers marching our offense down the field and scoring only to witness our defense lose the game in the last seconds.
Third, stats don't include the story of the game. Was the QB playing injured? How good were the players surrounding him? How good was the defense they were playing against? What were the ramifications/consequences of the game? A better idea would be to come up with a clutch rating system, assigning points to different levels of clutch ability based on the game situations, add them up at the end and divide by the number of games.