In 2007, Brewers right fielder Corey Hart appeared to establish himself as a championship-caliber player. The lanky, 6-6 Hart had long been considered one of Milwaukee’s best young talents, and in ’07 he put together an impressive .295/.353/.539 line in 566 PA. His walk rate remained low (6.7%, the same as 2006), but he upped his Isolated Power (ISO) from .186 in 2006 to .244 in 2007, a whopping 58 point increase. His 2.38 WPA/LI ranked 12th among all outfielders, and with 24 HR and 23 SB, he turned in a nifty 20/20 season. Just 26 heading into the 2008 season, Hart figured to build upon his breakout year.
Suffice it to say, that didn’t happen. Hart turned in a disappointing .268/.300/.459 line, with his ISO falling back to .191. His already tenuous walk rate dipped to 4.2%. Hart still turned in a 20/20 campaign (20 HR, 23 SB), but his WPA/LI fell by over two wins, down to 0.28 (the 20th-worst mark among qualified outfielders).
In 2008, Hart found himself behind in the count after the first pitch more than any other player in the game. Hart’s First Pitch Strike Percentage (F-Strike%) was an alarming 68.9%, nearly three percent higher than second-ranked Adam Jones. This wasn’t a one-year fluke, either: Hart’s F-Strike% has been over 60% in every major league season, pointing to an unrefined approach that often leaves him behind in the count before he can even blink. While most players show some improvement in their plate discipline as they gain big-league experience, Hart has progressively become more of a hacker:
Hart’s Outside Swing Percentage (O-Swing%), 2006-2008:
As he’s gotten older, Hart has devolved from a guy with a relatively patient approach to a free-swinging mess. His overall Swing % has also increased rapidly: 45.1% in 2006, 50.3% in 2007, and 54.7% in 2008. That 2008 number was the fifth-highest in the game. Swinging that often is okay if you’re shoe top hitter Vladimir Guerrero (who swung at a league high 60.3% of pitches seen) and you can make contact with 70% of pitches thrown outside of the strike zone, but Hart’s O-Contact% was a mild 54.5%, 14th-lowest among outfielders.
It appears as though pitchers identified a weakness in Hart’s game this past season. During his promising 2007 season, Hart saw a fastball 58.6% of the time. In 2008, he saw a heater just 51.7%, the 6th-lowest rate among all hitters. In place of those heaters, Hart saw a heaping helping of sliders, as his slider percentage increased from 18.7% in ’07 to 23.5% in 2008. Among qualified batters, only Hunter Pence, Dan Uggla and Geovany Soto saw a higher percentage of slide-pieces.
The game plan against Hart last season, particularly during his execrable second half (.239/.263/.396), became simple: get ahead of him 0-1, and then feed him a steady diet of sliders, knowing full well that he would be tempted to chase them out of the zone. The Bill James projection system sees a rebound season in store for Hart (.286/.336/.496), but he’s going to have to show some restraint against those outside sliders, lest NL pitchers make quick work of him again in 2009.