BJ, I agree with you that the Elias Sports Bureau's definition of a "clutch at-bat" is not very useful, and that defining any at-bat as clutch for the purposes of studying whether "clutch hitting" exists is nonsensical and arbitrary
. I do believe some players have a better chance of success in important situations based on how they handle pressure. Same thing with some players having less chance of success. Neyer's explanation of how MLB players are automatons unaffected by pressure only convinces me he has never been successful at the plate (assuming he has played at a certain level).
It's actually a complicated issue, but it's not a major concern to me since I dislike the "clutch-hit" term and feel that some consistant clutch ability (or more often lack of ability) applies equally to pitchers and fielders. This is related to some issues I do care more about though like whether hitting streaks exist or are just the law of averages at work. Often similar quotes from Mathematician Grabiner & Bill James are used in those arguments so these issues are related, and they usually bring out the strong opinions we've seen in this thread. Since it can't be proven whether any form of clutch hitting exists or not I think it might be wise to agree to disagree. That or just agree the Elias Sports Bureau's "clutch at-bat" stat is pretty useless.
Note: I usually play fictional OOTP, if I was very into OOTP as a historical simulator I would probably toggle a clutch hitting switch to the off position.