The Lost Platoon
If you’re reading a baseball blog you already know right-handed hitters hit left-handed pitchers better and the other way around. Baseball strategy revolves around it: lineups are shifted based to match up with the other team’s starter, managers often make multiple moves in one inning, LOOGY’s have careers, all for the sake of getting the right matchup. And it works- you don’t have to go any further that the Blue Jays 2007 season to see the effect it can have on a team: the club destroyed left-handed pitchers better than any other club in the American league, but struggled against even mediocre righties.
But did you know there’s (at least) another platoon advantage that’s almost as important?
“The Book” (an absolute must-read) looks at the handedness advantage and finds there is an average effect of 20 points (of wOBA, which is like a superior version of OPS but on the same scale of OBP). Nothing surprising there. But then look at the matchups between groundball/flyball pitchers/hitters and it turns out there’s a 16-point platoon advantage there as well. It works the same way-groundball pitchers fare much better against groundball hitters than they do flyball hitters, and vice-versa. It makes sense, really. If you swing down already and a pitcher is already throwing low, sinking stuff, you’re just going to pound it into the turf.
The effect of the two advantages are so close that if a manager gets one matchup right but the other one wrong, he may as well not have bothered at all. On the other hand, if he gets them right, a pitching change could have twice the effect. But have you ever heard someone say “ah, he’s going to the pen to get the grounder-grounder matchup?” No- instead people go absolutely bezerk if the platoon advantage everyone knows about isn’t followed to the letter.
One thing that makes the GB/FB platoon more difficult to take advantage of is that players are close to neutral when it comes to flyballs/grounders, while everyone is affected by the lefty/righty splits. But the Blue Jays pitching staff has some extreme cases, as they induced an incredible number of ground balls last season. In 2007 the Jays were tops in the league in groundball percentage at 49%, with one other team at 47% (Texas), one more at 46% (Colorado), and the rest at 45% or lower (the league average is 43%).
The only Jays starter who is a flyball pitcher is Shaun Marcum (40%). Roy Halladay was on the other end of the spectrum (53%). Here’s a look at how the average OPS of ground ball and fly ball teams these two pitchers faced was affected:
|Name||OPS effect on GB teams||OPS effect on FB teams||Difference|
Tampa Bay and Cleveland roughed up Roy so badly in a few games that overall, fly ball teams actually hit better against him than they did during the rest of the rest of their season. But the Doctor was just merciless against groundball-heavy teams. Marcum is the other way around, and the difference in his performances against each group is just as large.
While there isn’t much of a way to take advantage of this for starters, but it could easily be leveraged for relief decisions. Here’s who’s in the mix for the Blue Jays bullpen next year:
|Blue Jays Bullpen|
|B.J. Ryan (2006)||43%|
Even if you don’t need a double play, putting Scott Downs against left-handed ground ball hitters is a deadly combination, as 60% is among the very best in the league. On the other end of the spectrum, Brian Tallet should do relatively well against power hitters, who tend to be fly-ball hitters (like Frank Thomas, who lead the league in flyball percentage last year). That could somewhat explain how he managed to give up only one home run last season. B.J. Ryan provides a nice alternative to an otherwise groundball-heavy pen, and Brandon League was at an unheard-of GB% of 77% in 2006 (which is why J.P. emphasized the need for him to get his sinking movement back and not just the velocity on his fastball).
Unfortunately, it’s not likely that this will be taken advantage of next season (except for “gut moves” about what pitcher is right for a certain batter). The Book also confirms that big-league teams do not take advantage of this effect whatsoever. But at least now you can add another layer of complexity to your armchair managing and/or problem gambling.