Franklin Guttierez posted a .337 wOBA in 2009, well above his .316 career mark. He played as a 26 year old that season, so there was a good chance that entering his prime years, the improvement was real. It turned out not to be the case, as his wOBA fell to .300 in 2010. What happened.
The difference in the two years came from his hits (he walked more in the same number of at bats in 2010 compared to 2009). His batting averaged dropped 38 points. Note his hot zones in 2009:
Note how his best zones for getting hits lie on the edges of the strike zone. Normally, when pitches move away from the center of the zone, batters do worse, not better. Not surprisingly, those edge advantages disappeared in 2010:
Especially high in the strike zone, the areas where Gutierrez collected hits in 2009 turned into black holes in 2010. Franklin did hit better in the heart of zone, but that represents an area pitchers tend to avoid:
The Mariners outfielder got lucky on some bad pitches in 2009, making him look better than his career indicated. The good news is that Franklin isn't as bad as his 2010 number either. He does show good plate discipline, and at 28 years old should still be at his peak. He just needs his luck to swing back to the positive side of the ledger.