Oscar Taveras' theoretical existence, George Kottaras' signing, and Peter Bourjos' daring escape out of Mike Matheny's garden of forgotten toys have allowed the manager to shift his lineups from very lefty heavy to very righty heavy when he chooses. Last Saturday, against RHP Zack Greinke, 6 of the Cardinals' 8 position player starters batted lefty . On Sunday night, against the LHP Clayton Kershaw, the Cardinals reversed those numbers and started 6 position players who hit right-handed.
But all platoons are not created equal, and not all pitchers are equally vulnerable to the platoon. Here's a look at the Redbirds platoonability by position as well as a look at the rotations the Cardinals will face in the important divisional series down the stretch.
Catcher: Tony Cruz appears to be locked into the starter role for the time being, but George Kottaras has a career .330 wOBA against RHP, based largely on some legitimate power. Tony Cruz has been bad from both sides, and actually worse against lefties, but we're looking at very small sample sizes for each of these players, and platoon splits should be heavily regressed. Kottaras is probably a better hitter than Cruz against righties, but Cruz is a better defender, and the Cardinals are likely interested in seeing what he can do over a couple of months.
Platoon? No, but Cruz' off-days should come against RHP, especially when there's a short porch in right for George to swing at (all but one home-run in his career has been to right).
First Base: Matt Adams has struggled mightily against lefties in his career (.254 wOBA vs LHP .386 vs RHP), but at the moment there is no platoon partner for him. It should be noted that Oscar Taveras hit lefties well in the minors. If Oscar can establish himself, Adams should be the one who settles into a platoon with Allen Craig, who has been good against lefties even this year. More on that later.
Platoon? Not yet. But if Adams needs a day off, it should come against LHP.
Second Base: Kolten Wong looks like an every day player. Mark Ellis is 37.
Platoon? No. But Wong's off-days should be vs LHP.
Shortstop: There is only one SS on the roster. Jhonny Peralta is pretty good against righties and terrorizes lefties.
Platoon? No. That would be impossible since there is only one SS on the roster. John Mozeliak might want to address the issue at some point. I hear Pete Kozma is a good fielder.
Third Base: Matt Carpenter doesn't understand the question (.344 wOBA vs lefties, .367 vs righties).
Left Field: Neither does Matt Holliday (.386 wOBA vs LHP, .393 vs RHP).
Center Field: Much has been made on broadcasts of Jon Jay leading the league in hitting against lefties. That .388 number is shiny, but after just 48 AB's, it's also irrelevant. Over his career, Jon Jay has been a competent hitter against lefties (.319 wOBA) and a better than competent hitter against righties (.337). Peter Bourjos has slight reverse platoon splits .298 vs LHP, .311 vs RHP), but his identity as a high strikeout guy with slightly more power than you expect and a hot set of wheels remains intact either way.
Platoon? Yes, but a complex one. The difference in relative values based on the handedness of the pitcher has pretty marginal over their careers, but based on the recommended regression mentioned above with Cruz, it makes sense to platoon the players much of the time. However, Bourjos' extraordinary defense and speed make him especially valuable in spacious outfields, or if flyball pitchers Michael Wacha and Shelby Miller find themselves in the rotation again.
Right Field: Oscar Taveras is a top-tier hitting prospect and should play nearly every day so that he can develop his skills at the major league level. Allen Craig, despite his struggles in 2014, has a .342 wOBA against lefties this year (and .372 for his career). While Oscar didn't struggle against lefties in the minors, it is reasonable to let him find his footing against the pitchers he's most likely to hit while giving Allen Craig playing time against lefties.
What it all looks like:
The Cardinals have 3 LHB starters, 3 RHB starters, and 2 platoons to work with. Of the 6 entrenched starters, Cruz, Adams, and Wong all have backups whose opposite handedness allow for smart timing of off days. The team should regularly offer 5 position players with favorable platoon splits against any pitcher, and can bump that number to 6 while giving Tony Cruz and Kolten Wong rest if needed.
The Cardinals have 36 games remaining against the NL Central. Here are (most of) the starters they can expect to see. Bolded font indicates at least 20 points of wOBA benefit to batters hitting against the pitcher's weak side.
|wOBA agasint vs RHB||wOBA against vs LHB|
|Johnny Cueto (R)||.301||.307|
|Mat Latos (R)||.271||.301|
|Homer Bailey (R)||.311||.331|
|Alfredo Simon (R)||.325||.321|
|Mike Leake (R)||.316||.340|
|Matt Garza (R)||.308||.311|
|Kyle Lohse (R)||.320||.334|
|Yovani Gallardo (R)||.300||.319|
|Wily Peralta (R)||.291||.340|
|Jimmy Nelson (R)||too few IP||too few IP|
|Francisco Liriano (L)||.324||.264|
|Edinson Volquez (R)||.331||.335|
|Charlie Morton (R)||.297||.376|
|Gerrit Cole (R)||.304||.301|
|Jeff Locke (L)||.311||.313|
|Travis Wood (L)||.324||.271|
|Jake Arrieta (R)||.292||.343|
|Edwin Jackson (R)||.330||.345|
This Cardinals team isn't structured to allow mindless platooning, but there are clearly some ways in which logical lineup design can maximize team potency, both a la carte and with specific attention to the pitcher. For instance, the Reds and Brewers feature all-righty rotations, but it would make more sense to give Cruz off-days against Leake and Peralta than Garza and Cueto.