MLB playoff X-factors: One player who could swing October for every contender

Here's the X-factors for each playoff contender, the ones who could swing a series.

Freddy Peralta was a disaster for six weeks after Tampa Bay acquired him from the New York Mets on Aug. 3, a 7.17 ERA over his first four starts with the Rays. Over his last five starts, he's allowed just three earned runs in 28 ⅔ innings (0.94 ERA). He's not entirely fixed, though. His outing on Sept. 13 was a near no-hitter against the Houston Astros , but it still took 86 pitches to get through five innings because he walked three. If the newer version of Peralta shows up in October, the Rays have three dependable arms when including Drew Rasmussen and Nick Martinez . If the wild version shows up, the Rays might be walked out of the playoffs. If the version from August shows up, they are in trouble.

The Yankees postseason hangs on the health of Aaron Judge . Just back after missing three months with a broken rib, Judge seemed to be getting back into form when he left the series finale against the Twins on Sept. 16 with a right calf strain. Manager Aaron Boone said the team is planning for Judge "not being a part" of the Yankees' wild-card series, but Judge insists he shouldn't be ruled out . New York has to hope it's just part of the ramp-up process, because without Judge in the lineup, the Yankees' October could be very short.