Do Tigers Have Enough Relievers for Post-Season?

Nobody, whether it be local fans or national observers, doubts the excellence of the Tigers Tigers starting rotation heading into post-season.  The big four - Cy Young Award favorite Max Scherzer, American League Earned Run Average leader Anibal Sanchez, former Most Valuable Player and Cy Young winner Justin Verlander and rock solid Doug Fister - stand tall among America League pitchers by any measure.  If you like to look at innings and runs allowed, then all four All four rank in AL top fifteen in Pitching Runs. If you prefer to try to strip away factors such as team fielding which are largely beyond a pitcher's control, then they look even better with all four ranked in the top ten in Fielding Independent Pitching (FIP).

Not only do the Detroit starters have great regular season numbers this year, they also have past playoff success.  The quartet combined for an impressive 1.90 ERA in the 2013 post-season including a fantastic 1.30 ERA against the Athletics, their first round opponent again this year. 

Any questions about the Tigers pitching are about the bullpen.  They started the year without a real closer and eventually were forced to move set-up man Joaquin Benoit into that role.  They have been challenged by injuries to once reliable veteran Octavio Dotel and left-hander Darin Downs and disappointing seasons from the once amazing Al Alburquerque,last year's post-season closer Phil Coke and Venezuelan right hander Brayan Villarreal. 

While the Tigers bullpen has lacked depth, Benoit has been successful as a closer and young southpaw Drew Smyly, who could start for many teams, has done well in a variety of roles from long reliever to lefty specialist.  How good have they been?  Statistical evaluation of relievers is difficult for a couple of reasons:

1. They pitch so few innings that their statistics can be influenced heavily by a couple of really bad outings.
2. Their actual value depends on game situations more than any other player.

Using ERA to evaluate relievers is problematic because relievers often make appearances with runners on base and give up other pitchers' runs. So, a pitcher could have a low ERA without actually being that effective. The FIP statstic  which is based on walks, strikeouts and home runs allowed rather than runs allowed is better but it still does not consider the game environments in which a reliever pitched.

The RE24 (runs saved above average by the 24 base/out states) metric estimates the number of runs a pitcher saved or cost his team based on his numbers of singles, doubles and all other events allowed including outs, but also considers the situations in which these events happened.  For example, if Smyly enters a game with two men on base and nobody out and retires the side he will get more credit than if he comes in with the bases empty.  Smyly gets more points in the first scenario because there was greater potential for run scoring.  Thus, Smyly saves the Tigers more runs if he frequently pitches well with runners on base than if he always starts an appearance with the bases empty.

The RE24 leaders among American League playoff relievers are shown in Table 1 below.  Benoit (21.4) and
Smyly (17.0) trail only Red Sox closer Koji Uehara (25.9).  So, the Tigers are very strong at the end of the bullpen.  What the Tigers lack is depth especially with promising rookie fire baller Bruce Rondon out of the first round with a tender elbow.  The only other healthy reliever with a RE24 above 0 is Jose Veras (0.5).

Table 1: RE24 Leaders Among AL Playoff Relievers

Pitcher	Team	RE24
Uehara	Bos	25.9
Benoit	Det	21.4
Smyly	Det	17.0
Peralta	TB	14.9
Torres	TB	14.7
Breslow	Bos	14.5
Smith	Cle	13.2
Doolittle	Oak	12.9
Tazawa	Bos	10.4
Shaw	Cle	8.7

  Data source: FanGraphs.com

While the Tigers don't really have reliable relievers beyond Benoit and Smyly and to some extent Veras, bullpen depth in the playoffs can be a little less important in post-season than the regular season.  All the days off during the post-season will allow them to use fifth starter Rick Porcello as a middle or long reliever.  Porcello had an unremarkable 4.32 ERA, but he was an improved pitcher this year and should be an asset as a reliever.  Thanks largely to an improved change-up and scrapping his slider in favor of a curve ball, Porcello's strikeout rate has risen from 5.5 in 2012 to 7.2 this year and his FIP has dropped from 3.91 to 3.53.

Additionally, manager Jim Leyland has hinted that Verlander, the second-game starter, could pitch in relief in Game five if necessary.  So, the Tigers bullpen is not a strength particularly if they experience a long extra-inning game, but it's not a big weakness either.  I expect, they'll have enough quality relievers to get through the post-season just fine.