When the Rays traded Scott Kazmir for Sean Rodriguez, most of us here at DRaysBay were excited, and for good reason too. In 2009, in 108 games in AAA, Sean put up an OPS above 1 for the second consecutive season. Over the course of 170 AAA games in 2008 and 2009, Sean's wOBA was .438, a truly insane level. Sean cemented his status as an exciting player with a ballistic spring training, where he put up an OPS of 1.373 with a .460/.500/.873 triple slash in 63 at bats, earning his roster spot for the year.
That being said, we also had good reason for skepticism. The PCL and in particular Salt Lake City ballpark Sean played at are well known as being incredibly hitter friendly. Unfortunately, www.minorleaguesplits.com is down so we can't be certain the extent of Rodriguez's splits, but needless to say Salt Lake City has made hitters that are completely inept at the major league level look plenty good.
Rodriguez didn't exactly impress as the season began. In April and May, Sean put together a .255 wOBA despite a well above-average BABIP of roughly ~350. The reason for this was fairly clear: In those months, Sean struck out a combined 40% of the time, or roughly at the rate of strikeout king Mark Reynolds. Unlike Mark Reynolds, Sean didn't walk nearly as often as any hitter striking out that often should: his BB% of 4.3 was reaching into sub-Delmon Young territory. Despite this poor start, Sean's turned things around.
As we see, the last two months of the year Sean's dismal BB% picked up drastically. This is important as having a high BB% is a fundamental part of being a good hitter. As we've seen from John Jaso, walking at a high rate, while not rendering one slump-proof, does help a hitter provide value even when BABIP is frowning upon him.
What caused his uptick in BBs? Consider the following fundamental plate discipline statistics:
Rodriguez's plate discipline was excellent to start the year. He took more than 4 pitches each time up to the plate and swung at less than a quarter of pitches. Despite this, Rodriguez had a poor April and May because he was unable to walk at a high rate simply because pitchers were pounding the strike zone, causing him to walk rarely and strike out often. He was unable to take advantage of their pounding their strike zone, and put up below-average ISOs those two months (.105 and .106).
June is when things finally began to turn around for Sean. He pounded pitchers to a tune of a .205 ISO, and although his walks didn't pick up immediately, pitchers were no longer able to stay purely in the strike zone against him. His zone% dropped that month, never to pick up above 51% in the remainder of the year. Sean didn't show a particularly significant improvement in his plate discipline, but he merely started to swing at pitches in the zone more often and as a result get less of them.
Sean Rodriguez has followed a fairly normal path of developing into a better hitter. Don't chase pitches outside the zone, and pound the ones that are inside it. Obviously this is easier said than done, but hopefully Sean can continue to build from where he ended last year rather than from where he began it to continue converting his amazing tools into performance on the field.