Kevin Mench is a Free Agent

Kevin Mench was designated for assignment by the Brewers on Monday to make room for recently-acquired Salomon Torres, plucked from the Pirates for a couple of minor leaguers. As for Mench, the Brewers have ten days to trade the outfielder and his famously-large cranium else they must grant him his release.

Mench has five years of big league service team and is eligible for arbitration this offseason. The arbitration option disappears if he is released, as some team can snatch him up for something less than that. He made $3.4 million in 2007, and the collective bargaining agreement stipulates that he can't make any less than that in arbitration. That fact makes a trade extremely unlikely.

Mench is a career .271/.326/.465 hitter with iffy defensive skills. His batting line is unspectacular -- just 1% better than average over the course of his career -- and if you compare his production to other corner outfielders he doesn't come away smelling like roses. He doesn't run very well, and he has struck out almost twice as often as he has walked over the course of his six-year stint in the bigs.

The only reason we're still talking about him -- and the reason he has been a favorite of analytical baseball folks -- is that he absolutely destroys left-handed pitching.

Year	OPS vs RHP	OPS vs LHP
2002	.753	.825
2004	.792	1.036
2005	.744	.980
2006	.679	.877
2007	.564	.901
Career	.730	.924

I left 2003 out because Mench collected only 139 plate appearances for the entire season. His platoon splits are very dramatic; despite taking most of his cuts against righties he really hasn't done a very good job of figuring them out. Worse, his approach against them may actually be getting worse as he sees them more. Or, perhaps their approach is getting better as they see him more. Whatever the case, his reputation as a southpaw-masher is largely undisputed.

Mench might be a reasonable acquisition for the Mets, especially considering that they picked up lefty-hitting Ryan Church a couple of weeks ago in the trade which must not be named. Church has hit considerably better against righties than lefties (.352/.481 OBP/SLG against righties and .331/.392 against lefties).

If it were really that easy, every team would be employing platoons at positions where they can't currently pencil in a star player who hits well against both pitcher varieties. Unfortunately, strict platoons don't work very well for a number of reasons.

1. Players don't like it. Nobody enjoys being told that they aren't good at something, and professional athletes are no different. Whether or not Kevin Mench knows he sucks against righties likely doesn't change the fact that he doesn't want to be told as much.
2. It isn't really fair. Lefty/righty platoon splits are terrible unfair to right-handed batters, who would wind up with less than one-third of the aggregate plate appearances were the platoon strictly enforced. As an illustration of this point, the average MLB team had 4,563 plate appearances against righties and just 1,725 against lefties, which means that the right-handed portion of a platoon would only have accounted for approximately 27% of the platoon's plate appearances. Hardly equitable.
3. It's hard to do. The average big league starting pitcher threw just 5.79 innings per start last year. That number is even (surprisingly) lower in the National League, as elder-circuiters lasted just 5.73 innings per start. The average game lasted right around nine innings (8.97 to be precise), which means that starting pitchers accounted for less than two-thirds of each game. This fact poses logistical problems for any team looking to employ a platoon situation, as they can only guarantee the platoon advantage for six innings every game. Once the starter hands the ball off to the bullpen the platoon scheme becomes a crapshoot.
4. Platoon splits are an illusion. Okay, so I made that sound more dramatic than it really is. Most players exhibit some manner of platoon advantage, some small and others severe. The problem is that we can't look at Kevin Mench's production against lefties over the course of his career and conclude that he is a .924 OPS-er. That figure only tells us part of the story. The other part, the more depressing part, is that he is also a .730 OPS-er, in this case against righties and in far more plate appearances (1,664 versus 775).

   Mench's seeming ability to mash lefties is clouded by the fact that he has done so in slightly more than a season's worth of playing time. Jose Reyes had 765 plate appearances last season; Mench has the aforementioned 775 in his career against southpaws. Baseball history is littered with mediocre players who have excelled for one or two marvelous seasons before returning to their previous wretched forms. Mench is not a .924 OPS-er anymore than he is a .730 OPS-er. His true ability is somewhere in between, and over a large enough sample of plate appearances his platoon splits would begin to converge, resulting in a far less drastic disparity between his apparent effectiveness against lefties versus righties.

Mench wouldn't be a terrible signing, but bringing him in to platoon with Ryan Church in right field is problematic for all of the reasons listed above. The Mets already have Endy Chavez and Damion Easley in line to be backup outfielders next year, and Mench's usefulness coming off the bench is extremely limited. The Mets would probably be better served looking elsewhere.