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Jose Valverde’s Ground Assault

For most of his major league career, Jose Valverde has relied upon pure, unadulterated power to close out games. Delivering sizzling fastballs from a calm, unhurried motion that contrasts with the wild leaping and fist pumps that follow the recording of the final out, Valverde has punched out 10.7 batters per nine innings, issuing 3.62 BB/9 and posting a 3.48 xFIP in the bigs.

The former Diamondback and Astro inked a two-year, $14 million contract with the Detroit Tigers this past winter, with a $9 million club option for the 2012 season. Papa Grande hasn’t been scored upon since April 7th, a stretch of 23 appearances. Clearly, Valverde has been the beneficiary of good fortune — he’s got a 0.37 ERA, due in large part to a Houdini-like .136 BABIP, a 96.6 percent rate of stranding base runners and a 7.7 home run per fly ball rate. For comparison, Valverde’s got a career .280 BABIP, a 79.3 left on base rate and a 10.4 home run per fly ball rate. But his xFIP, 3.59, is right in line with his previous work. Same old Valverde, right?

Not really. In the past, the 6-4, 250 pound righty has been all about the fastball. He threw his heater in excess of 80 percent in 2005 and 2006, and used the pitch more than three-quarters of the time over the 2007-2008 seasons. However, there’s a clear change in Valverde’s pitching approach as of late:

(note: his Pitch F/X numbers don’t show the same changes in pitch usage. However, given that the pitches Pitch F/X classifies as fastballs have decreased several MPH this season, with a sharp decrease in vertical movement, I’m inclined to believe the system is lumping a lot of splitters in with the fastballs.)

After gradually decreasing his fastball usage in favor of a mid-80’s splitter over the past few seasons, Valverde’s percentage of heaters thrown has fallen sharply in 2010. He’s now tossing his fastball a little over half the time, going to his tumbling off-speed pitch over 44 percent. Valverde’s fastball sat at 93-94 MPH when he was airing it out with great frequency, but the pitch has parked at 95-96 MPH more recently.

The result of Valverde’s shift in pitching philosophy? Far more contact and ground balls than in years past. This season, opponents are putting the bat on the ball against the 32-year-old stopper 79.1 percent of the time, compared to a career 70.1 percent average. Valverde’s swinging strike rate, 14.4 percent during his career, is just 7.9 percent in 2010. His walk rate (3.7 BB/9) is basically unchanged, but his 6.66 K/9 is by far the lowest mark of his big league tenure.

While he’s not missing bats, Valverde has become an extreme ground ball pitcher. With a 68.3 GB%, Valverde trails only San Diego’s Ryan Webb and Atlanta’s side-arming Aussie, Peter Moylan, among qualified relievers. That’s quite the contrast to his career rate of grounders, 39 percent.

Amazing luck aside, Jose Valverde‘s results are right in line with his previous work. But the process behind those results has been drastically different. Rather than employing a fastball-centric, high K strategy rarely involving infielders, Valverde is going off-speed often and burning worms like few others.