Jason Kubel has demonstrated some new skills that he is excelling at in the 2010 season.
For instance, he has managed to become a level-eight expert at getting thrown out at home plate (not entirely his fault, mind you). He has also mastered the “what do you mean that was a strike, I was already bending down to remove my shin guard” face for all called strikes on three ball counts. He has almost perfected facial hair density (next year, buddy).
Here is another recent phenomenon for Kubel: He’s hammering curveballs.
From 2008 to 2009, Kubel destroyed more heat than images of a hot-tubbin’ Katy Bates in About Schmidt. He socked 32 of his 48 home runs while slugging .602 against the hard stuff. In that time, the lefty showed little indication of being able to wait on curveballs. In that same span, he it .221/.242/.379 against uncle charlies. What’s more is that he had little power as just three of his 48 homers hit came on benders. Not surprising, at the onset of the season, opponents decided to dial down the number of fastballs thrown to him. With less of his favorite pitch coming his way, Kubel saw a significant drop in his totals.
Back in April, I documented the decline in the amount of fastballs seen in correlation with his overall performance drop. At that time, while he was still making solid contact, Kubel was not the recipient of the desired results. Through May, the Twins’ DH/part-time outfielder was hitting just .233/.352/.397.
As opposing teams began adapting to Kubel, so too did the slugger. During the Milwaukee series at Target Field, at the behest of hitter coach Joe Vavra, Kubel moved his stance closer to the plate to increase coverage of the zone. Since that series, Kubel has hit .277/.341/.495 with 15 home runs in 349 plate appearance, producing closer to what has become expected of him.
This slight adjustment may also be the connection to his improved ability to stay in on and drive those hanging breaking pitches:

J. Kubel vs Curveballs
Well-Hit Avg
(via Inside Edge)
His slugging percentage on curves alone is currently the third-best in baseball. Only Aramis Ramirez (.833) and Scott Rolan (.808) have had more success than Kubel in this category. In addition to that, according to Fangraph.com’s Pitch Value, Kubel has turned in a 7.3 runs above average on curves, also the third-best in baseball. Not only is he hitting curves well, he’s helping score runs on those hits too.
Kubel production on breaking balls has become so prolific that this past Saturday, a day after he pounded a mammoth home run off of the Angels’ Dan Haren, FOX broadcaster Jose Mota noted that the Angels’ advanced scouting report recommended not throwing the Twins’ lefty curveballs altogether.
Once again, the word is out on Kubel. According to pitch f/x data*, just two of the 61 pitches Kubel had seen in Texas were curves. Heading into a weekend series in Seattle, don’t be surprised if the Mariners (a staff that does not toss many curves anyways) refrain from flipping any hangers in his direction.
*Note: pitch f/x data is not available from 8/23 game.