Predicting the results of a short series, let alone a whole tournament, is a fool’s errand. This fool, though, had some measure of success in attempting to do so last season with a model I called Playoff Runs.
The basic premise of the Playoff Runs model is that the talent on a team’s 25-man postseason roster will likely vary significantly from the results that team put up over 162 games, with various measures of injuries, designations for assignment, prospect call-ups, and trades changing the makeup of the team from week to week throughout the year.
The model assumes a certain volume of innings pitched and fielded and plate appearances from each of 25 roles on a standard playoff roster, assigns players to each of those roles, and multiplies each player’s Runs Above Replacement (for pitchers and hitters) or Runs Above Average (for fielders and baserunners) per inning pitched or plate appearance by the volume assigned to his role. A score is calculated for each team over a best-of-1-, 5-, or 7-game series and I anoint the team with more aggregate value on the field (or, more Playoff Runs) the likely winner.
Thanks to input from readers of this site and others, I’ve assembled the following table of likely participants in this month’s festivities:
[table id=317 /]
Starting with pitchers, let’s look at Runs Above Replacement per inning pitched in 2016, per Fangraphs. This includes games pitched for other teams, where applicable:
[table id=318 /]
These figures correspond to the same cells in the prior table, so you may have to maximize both tables to read them. The biggest number- that .447 in the left-handed setup role in the Cubs column- is Aroldis Chapman. Along with Kenley Jansen and Andrew Miller, Chapman tops the best starter (Clayton Kershaw’s .366) on a per-inning basis. The smallest number, -.070, represents Jeff Manship, who may or may not be on Cleveland’s postseason roster. As you’ll see below, it won’t make much difference.
On to the position players. Here are Fielding Runs Above Average (Def) per plate appearance for the players I expect to take the field at some point this month:
[table id=319 /]
As you may have ascertained, these figures include the positional adjustment, which is why most shortstops and catchers are positive, while most first basemen and corner outfielders are negative. I used PA as a baseline, rather than innings fielded, because the positional adjustment would make for some wonky numbers if a player was primarily a DH, but played a few innings in the field. The biggest numbers belong to two backup catchers: Washington’s Pedro Severino (.052) and Chicago’s David Ross (.043), who had just 33 and 205 PA, respectively. Severino will be forced into duty with Wilson Ramos injured, while Ross will be one of three catchers on the Cubs roster, something my system can’t account for, but which won’t make a material difference in the overall scoring. Among the regulars, Brandon Crawford and Francisco Lindor rank as the best fielders, having saved .043 and .041 runs per PA, respectively. The worst fielders both flank Adam Jones in the Orioles’ outfield: Hyun Soo Kim at -.030 and Mark Trumbo at -.027.
Let’s do the same for hitters, showing total hitting and baserunning Runs Above Replacement per plate appearance for the guys likely to bat:
[table id=320 /]
These lineups are all either actual lineups used at some point in the last week of the regular season or actual lineups tweaked to include a missing player or two. I gave all the NL teams a DH to put them on even footing with the AL teams. Obviously, these are more formidable lineups than we’ll see from NL teams before the World Series. The best hitter in the sample is Daniel Murphy at .107, with teammate Trea Turner riding an impressive performance over a small sample to the next-best mark (.105). Kris Bryant and Josh Donaldson are the only other players who added more than a run per ten plate appearances this year with their bats and legs. At the other end, backup catchers Caleb Joseph (-.083) and Robinson Chirinos (-.052) drag their teams’ Playoff Runs down the most.
The next step is to project how many innings each pitcher will pitch and how many plate appearances each player will get in the playoffs. We know that teams will lean on their top starters and best relievers to the greatest extent possible, and that players who hit at the top of the order will bat more than the guys at the bottom (by about 1/9 of a PA per lineup spot per game). Using some real data (for instance, starters averaged 5.8 IP per start this year, but the #1 starters on the ten playoff teams averaged 6.7) and some guesses (a best-of-five series has a 20% chance of ending in a sweep and a 30% chance of going the distance), I made these projections and multiplied them by a weighted expected number of innings in a series of each length (best-of-1, best-of-5, best-of-7). I checked the innings pitched assumptions against last year’s actual postseason pitcher usage and they were close enough not to recommend any tweaks this year. The only contribution for the player I deemed Pinch Runner was Baserunning Runs Above Average per game times an expected one opportunity per playoff game. The sum of the pitching, fielding, hitting, and baserunning scores gives us a team’s Playoff Runs.
Here’s how the four teams playing in the Wild Card games stack up in a one-game projection:
[table id=321 /]
The Blue Jays project to outpitch, outhit, and outfield the Orioles, even without their top starters available. Noah Syndergaard’s crazy strikeout rate helps push the Mets ahead of the Giants, though the model gives Madison Bumgarner no credit for his bat.
Here’s what all the playoff teams look like over best-of-five or -seven series. For simplicity’s sake, I did not shuffle starters around based on which teams are forced to burn their aces in the playoff games. It rarely makes a difference in terms of which team looks better than their potential opponent.
[table id=322 /]
[table id=323 /]
Three teams stand out above for dominating one aspect of the game. Boston’s offense is just over a run better than the runner-up Cubs and almost three runs better than that of any other American League team. The Dodgers’ pitching is more than two runs better than the runner-up Mets. Most impressively, the Cubs’ fielding is more than two runs better than the runner-up Giants. The Cubs exceed the average fielding team in the playoffs by 2 1/3 times more than anyone else. If Kyle Hendricks or Jon Lester wins the Cy Young Award this year, he should break off a chunk for Addison Russell, Jason Heyward, and Javier Baez.
The Playoff Runs model tells us that the Red Sox, Blue Jays, Cubs, and Dodgers are favorites to reach the Championship Series and the Cubs should beat the Red Sox for the title. The Dodgers’ proximity to the Cubs’ total score is probably the biggest surprise here, but it depends on Kershaw and Rich Hill being healthy enough to pitch deep into games, as their RAR/IP may be inflated by their low innings counts this year. Texas is the 9th best team in the playoffs by this measure, but they could easily reach the World Series just by beating numbers 10 (Orioles) and 8 (Indians)
For a look at each projected series, with notes about flaws in the model and how they could impact each series, read the companion piece here.