Over at Beyond the Box Score, Nathaniel Stoltz takes a look at what I consider the most questionable angle of Saturday's activity - the acquisition of Heath Bell. It's a long piece, and definitely worth a read in full, but because United won't yet let me add external stories to a stream, let's give you the Cliff Notes version. Initially, the prognosis is largely in line with the general opinion across the tubes if the Interwebz:
It seems particularly surprising that a team run by Kevin Towers, a bullpen-building expert if there ever was one, would seem to commit such a classic relief blunder. Committing $13M over two years to a pitcher who hasn’t really been effective in two years, and who is already 35, certainly seems like something a big-market team with backward management would do, not a club like Arizona that tends to be resourceful and has personnel that fit that reputation.
Stoltz points out that to justify the cost the Diamondbacks are taking on board, Bell needs to put up about 2.5 WAR over the lifetime of the deal. However, he notes that Bell has already got three single seasons, each of at least two WAR, on his resume: 2007, 2009 and 2010.
If Bell has another 2009-10 run in him for 2013-14, Pennington doesn’t fall off the face of the earth any more than he already has, and Young doesn’t suddenly metamorphose into a superstar, Arizona ultimately comes out just fine in this trade, getting about the same WAR production for the same price, but trading from a stockpiled outfield (.335 wOBA, ninth in MLB) to help out a weak shortstop spot (1.5 WAR, 27th in MLB) and fortifying a strong bullpen.
Stoltz's hypothesis is that Bell's issues started in 2010, not 2011 - however, they were masked by a pitcher-friendly BABIP of .261 in the former season, then exaggerated by a counter-balancing .341 BABIP this year. A loss of velocity doesn't seem to be responsible: "Last year, he averaged 93.6 mph on his fastball and 82.0 on his curve — in 2009, when he put up 2 WAR, his fastball was 93.6 and the curve 81.4." Movement and mechanics are similarly little chanced, leading Stoltz to conclude, "Bell still basically has the stuff that made him one of the game’s best relief pitchers — if anything, his stuff is ever-so-slightly better now than it was then."
[Towers] sees the same pitcher that did so well for his ballclub back then — same build, same delivery, same stuff, same approach to pitching. That pitcher was worth (per FanGraphs) $22.7M in the three years he pitched for a Towers-run organization (2007-09), and Towers thinks he can get back to that $7.5M/year form. In fact, he thinks Bell is in that form... There’s no clear reason why Bell can’t be as effective as he was in his heyday. The lack of an explanation for Bell’s issues appears at least as troubling as it is heartening, but given that Towers has personal experience with him, it’s understandable why he leans toward the optimistic viewpoint on the portly righthander.
It's an interesting concept - one which you may or may not agree with, but one which does appear to explain the logic behind the move, from an Arizona perspective.