If teams are looking for someone to throw to their hitters during the Home Run Derby, they could do worse than placing a call to Arizona. With a day to go, the Diamondbacks have allowed 49 home-runs in May, fifteen more than the next-worst in the NL Mets. If they allow two in tonight's game against LA, they'll have the most over a single calendar month by an NL team, since the pre-humidor days at Coors - the Rockies allowed 56 in August 2002.
It has been both the Diamondbacks' starters and relievers that have been getting tattooed. The Arizona bullpen has allowed eighteen in May, during only 284 at-bats; in other words, 19% of all hits they have allowed have left the yard. The rotation isn't much better, with a figure of 16%. Are they really that bad?
Previous studies show there's an element of chance in whether a pitcher has a ball become a souvenir, or just a long, loud out at the track. Since 2005, the percentage of NL fly-balls that turn into home-runs has consistently been between 7-8%. This year, it's 7.1%: for every other NL team, the number ranges from 5.0% to 8.4%. But, for Arizona, it's 11.2%: and it's not Chase Field, since from 2006-09, the D-backs number was always in the usual, 7-8% range.
Over a full season, no National League team since 2002 has had a number above ten percent - again, that dubious honor goes to the Rockies, before they started doctoring the balls. So, going forward, we should probably expect more of those Arizona fly-balls to turn into loud, breath-holding outs.
Will it turn the Diamondbacks' into Cy Young contenders? That's unlikely. However, there is some good reason to think they aren't as bad they have been. If someone were to offer me Dan Haren, cheap, in a fantasy league, I'd be very interested.