Dave Roberts’ Easy and Difficult Lineup Decision

Last night represented the sixth game of the Los Angeles Dodgers’ postseason run. Over the club’s first five playoff games, the left-handed trio of Andre Ethier, Joc Pederson, and Chase Utley recorded one start combined — specifically, Chase Utley’s in Game 3 of the National League Division Series against the Diamondbacks. That arrangement appeared to work: Roberts and company entered Tuesday with five consecutive wins. That’s what made the manager’s decision on Tuesday slightly unusual. Against Kyle Hendricks in Chicago, Roberts started all three players.

The gambit worked. All together, the trio went 3-for-10 with a double and home run. At one level, the decision was simple, logical. Because of the stage, however, it would have been easy for Roberts to go in a different direction. We often talk about how the postseason is different from the regular season, that it requires a different style of management. That’s no doubt true, particularly when it comes to the bullpen. There are instances, however, in which it’s also important to keep managing like the regular season. Roberts did that last night.

Letting Yu Darvish hit with the bases loaded is likely to get the most attention among Dave Roberts’ decisions last night, but attempting to maximize the platoon advantage against Hendricks was likely the more important move he made. During the regular season, teams face a lot more righty starters than lefties. This was certainly true for the Dodgers, who confronted righties more than two-thirds of the time this season: 114 of 162 games.

That ratio nearly flipped over the first five games of the playoffs, however, as Los Angeles faced left-handers Robbie Ray, Jose Quintana, and Jon Lester. That meant, in the early going of the playoffs, players who received a fair amount of playing time in the regular season weren’t getting the same type of shot in the playoffs. There was a pretty good reason to keep those platoons going. Here are a few of the part-time lefty batters the Dodgers have at their disposal and their lefty-righty career platoon splits.

We see that both Ethier and Granderson have compiled around 2,000 plate appearances each against left-handed pitchers and recorded pretty large platoon splits in the process. Those numbers represent the product of two long careers, and there is little reason to think either batter has suddenly changed this late into his playing days. We don’t have a big enough sample to say that Joc Pederson is a player who should be platooned. It’s possible he could improve his numbers the more he’s exposed to left-handers. What we definitely don’t have is any reason to think he is immune from at least typical platoon splits. Given a 111 wRC+ projection overall, that would make him average to below average without the platoon advantage.

Chase Utley’s numbers, meanwhile, are fairly even. He’s been a very good hitter for a very long time and has hit righties and lefties nearly equally well over the course of his career. However, since 2011 — a period covering 884 PA against lefthanded pitching — Utley has an 81 wRC+ against southpaws compared to a 112 wRC+ versus righties. What advantage he once had by being able to play every day and produce regardless of the matchup has dissipated with age. So we have four players who are better against righties than lefties but two other players, Logan Forsythe and Kike Hernandez, who’ve been getting most of the playing time in the postseason. They’ve shorter careers than most of the players on the list above, but look at their platoon splits thus far.

With regard to Forsythe, it’s probably worth nothing that he hit poorly at the start of his career, producing just an 84 wRC+ over four years and roughly 1,100 plate appearances with the Padres and Rays. In the last three seasons, though, he’s been close to average against righties with roughly the same gap seen above against lefties. It’s what makes him a solid everyday player, but that doesn’t mean Chase Utley might not be a slightly better matchup against righties.

As for Roberts’ preference for Ethier over Granderson, that move might seem a bit odd given that Ethier only has 64 plate appearances over the last two seasons. However, a lot of those plate appearances have occurred over the last month. In September, the Dodgers faced a righty starter 23 times. Curtis Granderson got a majority of those starts (13), but Ethier started eight times, too. The last time Ethier got a decent amount of playing time, back in 2015, he produced a 137 wRC+ as a platoon outfielder. He’s certainly diminished at age 35, but he might not be done. Ethier saw 11 pitches against Kyle Hendricks, and the typically patient batter swung eight times. He whiffed on four of those occasions, including three on the changeup, but he made contact with the sinker twice, hitting a homer and getting a single.

Moving past the hitters, there’s the question of the opposing pitcher — in this case, Kyle Hendricks. There appears to be nothing in Kyle Hendricks’ numbers to indicate that he’s likely to record unusual platoon numbers. On the season, right-handed starters against right-handed batters put up a .320 wOBA and 4.29 FIP and a .336 wOBA and 4.80 FIP. For Hendricks it was .274 wOBA and 3.53 FIP against righties and .309 wOBA and 4.27 FIP against lefties. For his career, he’s conceded a .260 wOBA and produced a 3.06 FIP against righties while recording a .301 wOBA and 3.89 FIP against lefties. Hendricks isn’t necessarily susceptible to lefty-heavy lineups. In matchups this season against teams with at least four lefties in the starting lineup, his numbers are the same as against righty-heavy lineups, but that platoon advantage is there and does show up in his overall numbers.

Platooning in the regular season should be a fairly simple task for a manager given the ability to spread playing time out over 162 games. In the postseason, we sometimes see teams trot out the same lineups or switch things up based on a hot hand or the perceived better player overall. The added pressure to win one high-leverage game after another can potentially cloud a manager’s decision-making. Dave Roberts is playing the platoon matchups just like he did during the regular season. Pederson — who wasn’t even on the NLDS roster — along with Utley and Ethier might not seem like guys to insert into a starting lineup after the Dodgers’ success earlier in the playoffs, but by using them like he did in the regular season, Roberts made the right move and it paid off.