Cust For a Low Cost

Jon Paul Morosi is reporting that Jack Cust will join the Mariners on a one-year, $2.5 million deal – the sort of contract that will once again allow Cust the chance to rack up surplus value for his team. In his career to date, Cust has been paid $6.165 million, and racked up 8.2 WAR for his teams.

It’s not too hard to see why his skills may be undervalued. In an off-season that saw Mark Reynolds traded for two relievers, a glove-less slugger that has struck out in 38.9% of his major league at-bats is not a sough-after entity. But along with those strikeouts come walks (17.3% career) and power (.207 ISO career). In fact, over his career, 53% of his plate appearances have ended in a walk, strikeout or home run. At least with the bat, he’ll help (126 career wRC+, 138 last year), so he can be your all-or-nothing DH if you shop in the bargain aisle.

Unfortunately, the trend in recent years has been a dissipation of his power. From a peak in 2006 (.248 ISO), his power has dropped every year until last year’s barely-above-average .166. At 31, and in full ownership of the “old people skills” that Bill James famously proved can erode quickly, that’s a worrisome trend. The thing is, isolated slugging is one of the last statistics to stabilize on a seasonal level, and Cust only accrued 425 plate appearances last year. Could he see a mini-bounceback in the power department with the Mariners? That seems paradoxical considering his new home park, but a straight-up comparison of park factors for lefties at the two parks doesn’t show much difference (92 park factor for home runs in Oakland, 91 in Seattle). Lefty pull hitters have even received a boost from Seattle’s park in the past.

What this means for Milton Bradley, though, is hard to see. Perhaps he’ll split time with Michael Saunders in the outfield, or maybe he’ll find a new team in spring training. Russell Branyan and his balky back will have to ply his trade elsewhere, for sure, and the extra million or so dollars the Mariners spent for Cust over Branyan were probably spent on getting slightly younger and slightly healthier.

A one-year deal for a DH at this cost won’t sink a team. If Cust merely repeats his worst season of his last four (2009, ~1 WAR, 9.4 runs batting), he’ll be worth the money. A decent trip through the penny store may have landed the Mariners a decent bat for the only position where brick hands won’t matter.