Tigers Pitching Staff is Average

As you probably know by now, the Tigers have been one of the worst teams in the American League in preventing runs this year.  In fact, their 4.74 runs allowed per nine innings (RA9) is third highest in the league.   You have also surely figured out that a lot of that is due to poor fielding.  However, pitchers need to be held responsible for their share of runs allowed and Baseball-Reference attempts to do that with their Runs Above Average (RAA) statistic.

How many runs a pitcher allows is affected by a few elements:

• The quality of his own pitching
• His team defense
• The quality of his opponents offense
• the ballparks in which he pitched

The team defense factor is measured by the Baseball Information Solutions Defensive Runs Saved (DRS) metric.  According to DRS, the Tigers fielder have allowed 0.34 runs per nine innings (RA9def) which is worst in the AL.  That would mean that the the Tigers fielders would allow 55 runs during the course of the season if they maintain the same pace.  That's bad enough, but some other metrics make them look even worse.  The Total Zone metric, for example, estimates that they would give up more than 100 runs in 162 games. 

As far as the quality of opponents, the Tigers have not faced a lot of really tough offenses to date.  The opponents runs scored per nine innings (RAopp) is 4.46 which is the third lowest in the league.

On the other hand, the Tigers have played in ballparks which favor offense to a small extent.  That includes Comerica Park for home games plus all opponent's parks.  They have a Park Factor (PPFp) of 101.6.  The average is 100, so the parks in which they have played inflate run scoring by about 1.6 percent. 

Baseball-Reference adjusts total runs allowed by the three factors described above and determines that the Tigers are 5 RAA.  In another words, the Tigers pitchers have saved the team five runs beyond what a staff of average pitchers would have been expected to allow under similar conditions.  The Yankees lead the league with 69 RAA while the Twins are at the bottom with -78 RAA.  So, the Tigers have close to an average staff, but it has been dragged down near the bottom of the league largely due to poor fielding.

Table 1 below shows that 2011 MVP Justin Verlander is second to The White Sox right hander Jake Peavy with 22 RAA.  Table 2 looks at the RAA's for all Tigers starters.  While Max Scherzer (-10) and Rick Porcello (-8) have not been quite as bad as their ERAs indicate, they have been below average pitchers so far.   The Tigers will probably need improvement from one or both of those pitchers if they are going to win the AL Central.  A healthy Doug Fister will go a long way too.

Table 1: AL RAA Leaders

Pitcher	Team	RAA
Peavy	Chi	23
Verlander	Det	22
Sale	Chi	21
Hammel	Bal	15
Wilson	LA	15
Paulino	KC	13
Kuroda	NY	13
Pettitte	NY	12
Sabathia	NY	11
Price	TB	11
Harrison	Tex	11

Table 2: RAA for Tigers Starters

Pitcher	RAA
Verlander	22
Fister	9
Smyly	6
Porcello	-8
Scherzer	-10