Paul Konerko was one of the best changeup hitters in the game last season, batting .324 and slugging .647 against it. This is a fairly significant rise over his .212 average and .423 slugging percentage off changeups from 2008 to 2009. What's most interesting is the shift in his power zones on changeups.
Prior to last season, Konerko was only producing power on outside changeups, and could do nothing against it on the inside half of the plate. However, he began to tee up on changeups coming inside in 2010. Whether it came from a lefty or righty made no difference. His high overall slugging percentage versus changeups was a result of a .654 SLG% off lefties and a .643 SLG% off righties throwing the pitch.
The increase in power was not without a drawback. Konerko's strike out rate increased 7.5% on changeups. Compare his 2010 SLG% heat map above with his contact rate below:
While Konerko didn't make great contact on changeups dipping down in the zone, his slugging heat map indicates that the ones he did connect on, particularly inside, he made the most of.