Oakland Athletics vice president Billy Beane once described baseball's playoffs as a "gauntlet of randomness" and on another occasion famously grumbled that "his [stuff] didn't work in the playoffs." While this could be taken as sour grapes, given that the 2000-2003 Moneyball-era Athletics lost all four of their division series appearances by a 3-2 margin, he does have a point when talking about the status of the postseason as a crapshoot. Simply put, there's a lot of inherent parity in the sport of baseball, so you have a lot of similar-quality teams facing off against each other in short series' matchups. Things like additional home games, a big deal in other sports, can only confer marginal advantages on baseball's regular season best.
That doesn't mean that the playoffs are completely random and projecting playoff performance is a lost cause. There are, in fact, some things that tend to improve relative playoff performance. Nothing to the degree of getting to use loaded dice when playing craps, more like getting to kick the roulette wheel once in a while without getting thrown out of the casino and banned for life. Baseball's all about chasing marginal gains, after all; it's why teams are willing to give up so much in late July to go from being a .550 team to a .560 team. So to answer which clubs are best built for the 2017 postseason, I asked the ZiPS projections to run the numbers for which teams had the best chance to punch above their weight class this postseason.
For the postseason, ZiPS uses a different model than the regular season when calculating team strength, one that puts a larger focus on the front-line talent and less so on the team depth. The biggest difference is how players are used. One thing I've worked quite a bit in developing a postseason model is analyzing how playoff rosters are constructed and how playing time is distributed. The playing time is weighed far more heavily to the starters, the rotation is truncated, and the best relievers are slagged with less concern for tomorrow. Also, when projecting the playoffs, ZiPS can focus more on the individual matchups, say, Clayton Kershaw vs. specific teams, which refines the projections further. The marathon is now a sprint, after all, and things like having the best fifth starter and a terrific spare outfielder simply mean less in October.