Casey McGehee’s Fast Start
by Eno Sarris //
Sometimes a player outperforms his minor league numbers by such a wide margin that it’s tempting to call it a Cinderella story on par with the imaginations of Bill Murray in Caddyshack. At the same time, the urge to dismiss such performance as luck is very strong as well.
To be fair to Casey McGehee, he did have an impressive debut. In fact, his .859 OPS in 2009 was the third-best OPS put up by a 26-27 year old debuting at second or third base since 1901 – if you set a 350-at-bat and 15-home run threshold. That threshold is significant, though: The power is the most surprising part of his game, as we will see.
First, let’s appreciate how nicely McGehee is following up his debut season. Since McGehee is eligible at second base in most leagues, we can take a look at how he stacks up against other second sackers in the spider chart on the right from Bloomberg Sports Fantasy Tools. Sure, he’s not giving his owners many stolen bases, but otherwise he’s been more than solid. See those three dots clustered around McGehee in the scatter plot? They represent Dan Uggla, Chase Utley and Dustin Pedroia. Heady company for the young Brewer.
But this sort of debut didn’t seem to be in the cards, based on his pre-major league career. His combined minor league line was .279/.332/.409; now, 518 plate appearances into his major league career, his line with the Brewers is .295/.355/.496. Maybe there’s something in the water (or beer) in Milwaukee. Of course the question is whether or not he can continue his elevated play, because those 2,800 minor league plate appearances weigh heavily against that proposition.
First, let’s look at his patience. McGehee has been showing an average walk rate in the majors (8.9%) and he’s bumped that up this year (12.1%) by not swinging… at anything. Swing rate is significant early in the season, and his 37% swing rate makes him the 20th-toughest player in baseball to coax into a swing this year. While he didn’t have great OBPs in the minor leagues, McGehee had above-average walk rates many years. Combined with his current swing rate, it looks like he’s become a more patient hitter and that his nice OBPs may continue.
The million dollar question, however, is if he will continue to show the same power. His isolated power (SLG% – BA) is .257 this year, .200 for his major league career, and .130 for his minor league career. That’s a stark difference right there. A quick check of the sample sizes needed for certain statistics to become significant shows us that ISO is one of the last offensive statistics to do so. In fact, McGehee has not yet reached the level of plate appearances at which his ISO would become significant, counting his career major league plate appearances (let alone one month worth of data this season). In other words, other players that racked up fewer than 550 plate appearances had an ISO that was less than 70% correlated with their future ISOs.
The strongest sign that McGehee’s performance will start correcting is his HR/FB rate. Right now he’s hitting fewer than a third of his balls in the air, yet 18.5% of them are leaving the park. That percentage is on par with Justin Upton, Adrian Gonzalez, and Evan Longoria, some of the most powerful sluggers in the game.
Unfortunately for McGehee and his owners, that’s the part of his game most likely to regress toward the mean. McGehee would still remain a playable option in mixed leagues if his power numbers fall back to Earth. But if someone in your league sees him as an elite infield option, you should consider looking into a trade.
For more on Casey McGehee, Martin Prado and other players outperforming their minor league statistics, check out Bloomberg Sports Fantasy Tools.