Post-Petco, Relievers Not As Bad As You Think

Yesterday, the Padres traded reliever Ernesto Frieri to the Angels, in exchange for Minor Leaguers Alexi Amarista and Donn Roach. Frieri has pitched very well thus far this season, with walk and strikeout rates significantly better than he had in 2011, albeit in a much smaller sample. But will the Angels be getting that pitcher? Petco Park seemingly has a way of elevating mediocre pitchers into above-average, or even elite ones. That has never seemed as prevalent as it has this year, as we have watched Heath Bell struggle to put away the likes of Joaquin Arias and Travis Buck.

Plenty of relievers have pitched at Petco since it opened, but in order to get a good sample here we need to make sure that we have pitchers who have pitched significantly at both Petco and somewhere else following their tour of duty in San Diego. 97 relievers have pitched in Petco and then moved on since the park has opened, but 58 of those threw less than 15 innings in their last stint with the Padres, so we’ll knock them out right away. Of the remaining 39, four are those who have just left following the 2011 season — Bell, Frieri, Chad Qualls and Pat Neshek — so we will eliminate them as well. Another 14, Rod Beck, Paul Quantrill and Brian Sweeney among them, either never pitched in the Majors again or didn’t pitch enough to be given consideration (Sweeney is an interesting case, as he went to the Japanese leagues for three years before coming back to the Mariners in 2010, but since that’s not Major League ball we’ll leave him out as well).

That leaves us with 21 pitchers. Of the 21, 14 only pitched in the Majors for one to two more seasons, and of the 21, the only two who stayed with their next teams for three years or more were Scott Linebrink and Dennys Reyes. Since many of the 21 only pitched for the Padres for one season or were in the Majors for one season after leaving San Diego, the comparison will go for one full season after they left the Padres. So for the five players who left during a season — Linebrink, Mike Adams, Sean Gallagher, Glendon Rusch and Royce Ring — it will include the remainder of their season with their new team, as well as the year after. It’s not the best, but it’s what we have. I also amended the rule for Clay Hensley, who after leaving the Padres following the 2008 season, didn’t pitch in the Majors in ’09 but did make it back in ’10.

* Includes remainder of last season after being traded/released from Padres

Well, that wasn’t what we were expecting at all, was it? By and large, this sample of pitchers was significantly better after leaving Petco Park. I’m tempted to remove Rusch from the sample, since he was used as a starter for part of his time in Colorado, but doing so doesn’t materially alter the results (the FIPs change to 4.01 and 3.73, respectively). In fact, it doesn’t seem like the differences are necessarily linked to one player at all. No reliever had better than a 2.0 WAR season after leaving — there’s no 2003 Eric Gagne performance here. The pitchers were simply better elsewhere. 12 threw more innings in their next stop, 14 had a better FIP and 15 had a better WAR.

Now, this is by no means conclusive. For starters, it’s only 21 pitchers. Second, the samples are small on both sides of the ledger, and that is compounded by the fact that relievers in general can have wildly varying performances from year to year. Second, I’m not looking actually isolating their home and road splits to isolate exactly how good they were at Petco, just their overall lines (boiling it down to splits would dilute these already small samples even more). In addition, by filtering out pitchers who didn’t throw a lot of innings, the sample is more likely to contain good pitchers. Furthermore, these pitchers were either getting on in age (i.e. Embree, Hoffman) or weren’t that great to begin with, since most weren’t in the Majors for that much longer after their year-plus-one season, and intuitively, that should tell us that maybe these guys weren’t as good as these numbers indicate — at least not long-term.

This sample of pitchers doesn’t necessarily take a chainsaw to the old adage that pitchers are awful once they leave Petco, it certainly plants an axe firmly in its base. Ernesto Frieri might not end up being a great long-term investment for the Angels, but Heath Bell’s continual meltdown aside, we shouldn’t necessarily assume that he will be useless for them either — particularly this season.