The book on David Aardsma was always the same: power arm with a blessed fastball, but wild command and an affinity for fly balls – and by extension, home runs. He was essentially a major league journeyman. The former first round pick out of Rice had spent the first few seasons of his career within the Giants organization but only appeared in big league games for the club in 2004. His next major league appearance would come for the Cubs in 2006. In 2007 he’d stay in Chicago, but move to the Southside. In 2008 he’d remain a Stocking, but change hues from Black to Red.
Think about that. Aardsma pitched in every season from 2006 to 2009 and never spent time with any one team in consecutive seasons despite a live arm. That all changed in 2010 as Seattle became his home. His first real major league home. Consistency in role and location is supposed to make players better, right? Aardsma probably has a real comfort level with how the Safeco bullpen mound translates to the playing field mound. And how Safeco’s dimensions play on humid days and cool days alike. He mostly knows the divisional foes and how potent or weak their lineups are. That should make a player a little more aware, a little better.
Except it hasn’t; at all. It would be ridiculously unfair to expect Aardsma to fully replicate his 2009 season. He posted a 3.01 FIP, a 4.12 xFIP, and a 2.53 ERA. Those are pretty good numbers from anyone, but he always posted a 4.2% HR/FB and a career low groundball rate (25.3%) which, well, nobody needs to have what regression means spelled out to them. Moving forward, it was simply unrealistic to expect Aardsma to have that kind of luck continue. This season, his HR/FB is up to 12.1%; nearly a career high and well above his average. He’s gotten a few more groundballs than last, but his ERA is over a 5, his FIP is over 4.5, and his xFIP is 4.32.
Not much has gone right for the Mariners this season, and Aardsma is another example. While none of the projection systems figured he’d post an ERA less than 3.5 or a FIP less than 3.97; they also didn’t have him as one of the worst relievers in a bullpen that’s failed to impress. Nobody should’ve seen 2009 Aardsma walking through that door again, but nobody should expect to see 2010 Aardsma to continue at this pace either.