A reader points out that while the Yankees outperformed their regular-season Pythagorean record during their golden age of 1996 to 2001, they outperformed it even more during the six-year age of silver that followed - which suggests, in turn, that the effect is a combination of statistical noise and the impact of Mariano Rivera (a constant across both eras) on close games than the any roster-wide "we know how to win" killer instinct. Henceforward, then, I pledge to confine my mythologization of those late-nineties teams to their astonishing postseason record, and I'll leave their ability to beat the "runs scored versus runs allowed" odds out of it.
Also, another reader notes that the '01 World Series ended in November because of 9/11-related delays. So Olney's "last night" was a November night, not an October one as I suggested below.
Finally, here's John Schwenkler's midseason meditation on the end of the Yankee era.