Missing the Platoon Advantage

Well, dropping two of three games to the Trout-less Angels this weekend really took a lot of the steam out of the series win over Houston last weekend. The Red Sox’s offense has an annoying habit of making mediocre pitchers, like J.C. Ramirez and Parker Bridwell for example, look really good. That is probably par for the course from what has been an average group (4.7 runs per game, .262 TAv). Being average is fine, I guess, but it is well below preseason expectations. There are, of course, multiple reasons for the worse-than-expected performance, but the one that continues to stand out to me is how injuries have dramatically reduced the flexibility of the roster. In the team’s current state, the lineup is mostly a set-it and forget-it situation. And those who start the game, tend to finish it: the Red Sox have the fifth fewest plate appearances by substitutions in the American League this season. That could be taken as a criticism of John Farrell’s managing, but it is not meant to be one. Given the injuries and personnel, there is just not much tinkering to be done with the current group.

The clearest example, to me anyway, of an injury limiting the Red Sox’s roster flexibility is Hanley Ramirez’s bum shoulder. The injury is preventing him from playing first base, and it is sapping his power: he has a career low isolated power of .167, which is another one of the many reasons the offense is underperforming. But let’s focus on the defensive aspect of the injury. Hanley’s inability to handle innings on defense has a knock-on effect that limits the team from consistently gaining a platoon advantage. If Hanley plays first base on days the Red Sox are opposing a left-handed pitcher, then Mitch Moreland can have a day-off (as he does not typically fare well against lefties), and lefty-masher Chris Young can slide into the designated hitter spot or even play outfield, thereby giving one of the young Bs a day at DH, and a pseudo-day-off. Taken together, that all sounds great: get an opposite handed batter into the lineup without losing too much on defense, and get guys a bit of rest. But Hanley can’t do it. So Moreland plays first everyday (he has played in 70 out of the Red Sox’s 75 games), regardless of the handedness of the opponent, and Young ends up with sporadic playing time that doesn’t necessarily align with his strength. Consider that the reduced flexibility I just described is just the outcome of Hanley’s issue. Factor in the losses of versatile, multi-position players like Brock Holt and Marco Hernandez and the roster becomes even more rigid.

Missing out on platoon advantage situations is a negative aspect of roster rigidity. Over and over again we hear about the advantage batters have when confronting opposite-handed pitchers. Maximizing these opportunities through day-to-day lineup adjustments, like those I described above, and late game pinch hitting decisions can boost an offense. Unfortunately, to date, the Red Sox have not been able to do so. According to the data available on Baseball Reference’s Play Index Splits Finder, through Saturday’s game, only 47.1 percent of the Red Sox’s offensive plate appearances have been with the platoon advantage. That percentage, almost half, might not sound so bad, but it is the fifth lowest percentage in baseball and a long way behind the Cleveland Flying Franconas’ league-leading mark of 71.85 percent; life is nice when you have three switch-hitters in your everyday lineup. Converting all 43 of Mitch Moreland’s plate appearances against lefties to Chris Young doesn’t shoot the Red Sox to the top of charts on this measure, but it moves them up a few spots and, most importantly, would likely have increased the production they got in those plate appearances.

You’re not going to platoon Mookie Betts. That would be absurd. He hits everybody well. But Chris Young hits lefties much better than Mitch Moreland. Brock Holt will hit a fireballing right-handed reliever better than Christian Vazquez.

The platoon advantage is not everything. Many poor offenses have had a large percentage of their plate appearances set up in their favor by handedness, and many of the strong offenses have often faced a disadvantage by handedness. At the team level, the correlation between percentage-of-plate-appearances-with-the-platoon-advantage and TAv is basically zero (r² = .001). After all, good players and teams can (and likely will) perform well, regardless of the advantage. It is when a team can reliably exchange a situation that presents as a disadvantage for one that is advantageous (or at least better) that the benefit can show up. You’re not going to platoon Mookie Betts. That would be absurd. He hits everybody well. But Chris Young hits lefties much better than Mitch Moreland. Brock Holt (or even Marco Hernandez) will hit a fireballing right-handed reliever better than Christian Vazquez. These are the situations that could be exploited by the Red Sox, but the lack of lineup flexibility presented by their injuries prevents it from happening.

It is worth noting that the Red Sox’s low percentage of plate appearances with the platoon advantage is not only present with the offense. On the pitching side, teams ideally get as many same-handed matchups as they can, but a rotation of Rick Porcello and a series of lefties (Chris Sale, David Price, Drew Pomeranz, Eduardo Rodriguez, Brian Johnson) limits the extent to which that is possible. Accordingly, the Red Sox’s pitchers have only had the platoon advantage in 41.09 percent of their matchups, which is the second lowest mark in baseball, ahead of only the Kansas City Royals. Terry Francona and his boys are on top here as well, with 53.83 percent of their matchups being same-handed affairs. The Red Sox are a top-10 team by runs allowed, so all these disadvantaged plate appearances are not killing them – at the team level, the correlation between percentage-of-plate-appearances-with-the-platoon-advantage and RA is a little stronger than the comparison for the offensive numbers, but not much better (r² = .088).

Combine the offense and the defense and the Red Sox have had the platoon advantage the second least often in baseball:

In the end, it is really difficult to know what to take away from this fact. On the one hand, the lack of lineup flexibility and predominantly-left-handed rotation have put the Red Sox in less advantageous situations more than almost any other team in the game. But, on the other hand, they are in (or very near) first place, have strong pitching and defense, and the expectation is that the offense, even as currently constituted, can be much better. It would certainly be a lot of fun to watch a Red Sox team that mixes-and-matches, and uses all of its parts in order to give players the best chance to succeed as often as possible. Given the way things are looking health-wise, it seems as though, for this year, the Red Sox are going to keep plowing toward the finish line with the more straight-forward, everyday-nine approach.

Photo by Troy Taormina – USA TODAY Sports