Schilling never had 2 series in a row with awful numbers, let alone 3, like Beckett.
Beckett's 73+ IP sample size was pretty significant, before the boom came down.
How about Mr. October, himself? Reggie Jackson. No denying the guy went on a rampage in the playoffs for quite some time, but then what happened?
He went about 218 PAs being "da man," but then went 20 for 91 (.220) over his last 100 PAs.
He still had an OPS over .810 in that time frame during the regular season, so did he just lose that "clutch skill?"
Maybe, he wasn't really all that clutch and just got hot in a few late season series.
Career
.846 OPS
.804 Late & Close
.855 High Leverage
.885 post Season