Nick Swisher has been a valuable hitter for the Yankees since joining the team in 2009. He's averaged a 123 OPS+ in that time, hitting 81 home runs over his three seasons in pinstripes. However, he hasn't yet been able to carry that success into the postseason.
His slugging percentage heat maps suggests that the switch-hitting right fielder has been unable to duplicate his success on pitches in the zone in the postseason.
During the regular season, Swisher did quite well on pitches up in the zone (.491 SLG%). However, through 110 postseason plate appearances as a Yankee, his numbers have fallen short, as he's slugged just .296 on pitches in the upper portion of the zone.
One interesting note: since joining the Yankees in 2009, Swisher has a .302 batting average on balls in play during the regular season. In the playoffs, that number is down to .169. He's seen his fly ball percentage jump slightly from 34.3% in the regular season to 38.6% in the postseason, while his line drive rate has dropped from 19.5% to 14.3%. However, in the regular season, Swisher has produced a .798 batting average on his liners. Yet in the playoffs (SSS caveat), only six of his ten line drives have translated into hits. In addition, his ground ball batting average dropped from .238 in the regular season to .185 in the postseason.
It's possible Swisher has been somewhat unlucky as a Yankee so far in the postseason, while he's probably also not hitting the ball as well either. Although, it's also important to note that teams generally face better pitching come October. So combined with an overall small sample size of data, it's not uncommon for hitters to see a decline in their numbers this time of year.