When we evaluate an MLB team’s roster, we tend to just look at their opening day starting lineup, which is referred to as their “starting nine”. However, as teams get smarter, it’s clear that we can no longer make those types of evaluations. After studying winning teams, one common theme became apparent- their “starting nine” is more like a “starting twelve”. So, how are these teams benefiting from platoons? Let’s take a closer look.

Platoons have generally been used as a derogatory term when a team doesn’t have a starting-caliber option at a position, as it’s generally thought of as a negative to not have one player capable of starting 150+ games. Yet, that couldn’t be further from the case. At the end of the day, what matters for the team is the cumulative Wins Above Replacement (WAR) that they can generate at each position, and if that WAR is coming from two players, it’s worth the same as if it was coming from one player- you can compensate for a player’s shortcomings by having them split time with a different player.

Even with the benefits of a platoon, teams would still prefer to have a player at each position capable of being an everyday player. However, there is one position where a timeshare is almost a necessity- catcher.

Since 2015, Buster Posey and Yasmani Grandal are the only catchers to play 150+ games in a season, and even then, both played over 20 games at first base. Therefore, there is a clear need to have a strong backup catcher, considering they’ll play more games than the traditional bench player, but for the sake of accumulating the most WAR, teams ought to limit the playing time of their starting catcher even further.

To illustrate this, let’s look at the relationship between WAR and plate appearances for catchers versus the relationship between WAR and plate appearances for non-catchers. If there is a weaker relationship for the catchers’ scatterplot, it would reaffirm the idea that there isn’t much benefit to having one catcher play a majority of the games. To try to balance out the sample sizes, we’ll go through 2015 for catchers, while just looking at 2019 for non-catchers:

Although it isn’t by as wide of a margin as I thought it’d be, it is apparent that there is a slightly weaker relationship for WAR versus plate appearances for catchers than non-catchers. In other words, the more than catchers play, the more likely it is for their production to diminish, making a timeshare even more logical- they’ll accumulate more WAR from the position that way.

What if your catcher is one of your best hitters? Well, teams are in luck! With the universal designated hitter almost a certainty to be implemented permanently by 2022, you can keep a catcher’s bat in the lineup without having them play first base, which leads to a stronger lineup in general. This would obviously place a greater emphasis to acquire catchers who have adequate offensive ability, but with the automatic strike zone likely to come into play, it’s likely that catcher defense won’t be a major factor soon anyways. So, technically, setting up a split timeshare for their catchers right now would allow teams to get ahead of the curve by adjusting for two huge critical rule changes, and as we know, if you aren’t early, you’re late.

Is this definitely a solution to getting better production from catchers? There is a lot of logic behind it, but until we see this play out, we won’t know for sure. Still, there are some noticeable examples of this working for teams:

• 3 of the top-11 catchers in WAR last season played under 100 games.
• The Twins got 5.5 WAR out of their catchers by engineering a platoon between Mitch Garver and Jason Castro, which is very similar to what JT Realmuto was worth.
• Realmuto was worth more WAR, but since Yasmani Grandal was more efficient as a catcher and Manny Pina proved to be an adequate backup option, the Brewers accumulated more catcher WAR than the Phillies.
• The Dodgers lost Grandal this offseason, yet still ranked in the top 8 in catcher WAR this season. They did this despite not having a catcher rank higher than 15th (Will Smith) in WAR.
• The Diamondbacks followed the Twins’ model by having Carson Kelly and Alex Avila equally split time behind the plate.
• Willson Contreras’ worst season with the Cubs came when he played the most games, as his second-half production declined. He was much better this season, which may have something to do with the fact that Chicago limited his playing time.

It’s impossible to know if the idea of a catcher timeshare will become adopted by more teams. However, with an extra roster spot and the new rule changes coming, the logic would indicate that this will become more popular. For instance, it appears that Farhan Zaidi, the President of Baseball Operations for the Giants, has bought into this strategy. Despite having one of the top catching prospects in baseball in Joey Bart, he still drafted catcher Patrick Bailey with the 13th overall pick in this year’s draft, and has made it clear that he envisions both being a part of their long-term plans. That hasn’t stopped evaluators from chastising Zaidi, saying that the team had greater organizational needs. However, his vision of a Bart/Bailey duo could work out tremendously. In a perfect world, they’ll have two above-average catchers, and together, they’ll be able to give the Giants assurance that they’ll rank at the top of the league in catcher production. In general, drafting the best player available, as well as stockpiling at such a valuable up-the-middle position like catcher, is a great approach for any team to have. As Zaidi demonstrated, the idea that you only need one catcher is foolish, and while other teams may be scared to have “too many” catchers, Zaidi took advantage of a market inefficiency. He has a tough task rebuilding an organization without much young talent, but he’s more likely to achieve his objectives by being an innovator rather than being a follower.

The Giants, Twins, Diamondbacks, Dodgers, Braves, and Brewers are among the organizations that have really bought into the idea of a catcher timeshare. What do these teams have in common? They all have very smart front offices, and should be satisfied with the overall production they get from their catchers moving forward. At the very least, teams need to value their backup catcher spot like NFL teams do with backup quarterbacks. However, platoons, especially at a talent-deficient position like catchers, are a very effective way of team-building. It’s very difficult to have every position filled by one player capable of playing every day, so having timeshares at certain spots can help teams better build a deep roster, while also maximizing on specific player’s overall efficiency. With the universal DH, an extra roster spot (already established), and an automatic strike zone likely all coming into place soon, teams need to be planning ahead. The teams mentioned above are the innovators of this idea, and if others don’t act now, they’ll be missing out on a clear market inefficiency.