A Platoon Strategy for Tyler Flowers and Travis d’Arnaud

We are, for now, still in the pitch framing era. Ten years from now, framing will likely be such a fundamental aspect of catching, no player will make it to the big leagues at the position without being good at it. And when everyone is good at it, no one really is! For now, however, we still watch a form of baseball where many catchers are demonstrably better than others at stealing strikes on the edges of the zone. Atlanta, as you well know, has one of the finest catchers when it comes to this particular skill, Tyler Flowers. This offseason, they signed Travis d’Arnaud, an excellent framer in his own right as recently as 2017. There is no question, however, that Flowers is the framing king of Truist Park.

There aren’t a lot of easy, obvious ways to divide playing time between Flowers’s and d’Arnaud’s bats. Both are right-handed hitters. Both are projected by ZiPS to have an OPS+ somewhere south of league average - Flowers at 83, d’Arnaud at a slightly better 89. PECOTA agrees, projecting d’Arnaud for a 91 DRC+, with Flowers at 87 in the same metric. d’Arnaud has preferred to hit against lefties whether looking at his entire career (117 tOPS+) or 2019 (127). Flowers’s preference is less pronounced, but he has also hit better against lefties (106) over the course of his MLB career. In 2019, Flowers enjoyed a reverse split, hitting better against righties (122), but that is likely an aberration. From a results standpoint, without getting into how each fares against a specific type of pitch or anything similarly granular, the Braves have two similar catchers at the plate.

If they’re similar at the plate, then what about behind it? If there isn’t an obvious way to platoon their bats, could the Braves platoon their gloves? While the concept of platoons typically involves finding ways to help the platooning players perform against that day’s opposition, Atlanta could choose a platoon schedule for the catchers that instead helps their teammates. Not all aspects of catching are measurable, of course, and if a pitcher prefers d’Arnaud’s pitch calling, for example, it would be hard for us to recognize that aside from making results-based guesses. So for the purposes of this exercise, let’s just assume that all other things are equal (though they may not be) and the Braves want to maximize the benefits of Tyler Flowers’s glove while maintaining a timeshare that keeps everyone well-rested- something Flowers himself would certainly enjoy.

Photo by Julio Aguilar/Getty Images

With which pitchers would Tyler Flowers’s prodigious pitch-framing be most useful? To begin with, let’s take a look at Flowers’s greatest strength: the edge of the strike zone. Not every pitch framer is made equally. A catcher might excel at framing pitches low rather than those along the upper boundary of the zone. Some catchers fare better on pitches to their left rather than pitches toward the right. Via MLB’s baseballsavant.com, we can see visual breakdowns of every catcher’s abilities in every section of the edges. Here are how our catchers fared in 2019, with the called strike rate in each zone, from the catcher’s perspective:

Up and Left: TF - 22.1% / TD - 22.0%
Up Middle: TF - 53.6% / TD - 56.8%
Up and Right: TF - 11.7% / TD - 27.2%
Left: TF - 64.5% / TD - 62.5%
Right: TF - 67.4% / TD - 63.5%
Down and Left: TF - 35.7% / TD - 26.9%
Down Middle: TF - 62.1% / TD - 50.2%
Down and Right: TF - 35.9% / TD - 24.5%

At first glance, you might see similar percentages to the right and left, and see d’Arnaud looking better up high while Flowers excels low, and think, “Why is one considered so much better than the other?” Unfortunately for d’Arnaud, more pitches are thrown on the sides and lower end of the strike zone, and those are the areas where Flowers has a clear advantage.

So, which pitchers would get the most out of having Flowers behind the plate? First, we need to look at how many pitches each prospective starter throws to each framing zone.

To illustrate, those are the pitch percentages, out of ALL pitches, that those pitchers throw to each zone. I then applied the called strike probabilities from earlier for each catcher, and calculated the expected framing strike advantage for Tyler Flowers based on each pitcher, over a 100 pitch sample.

But there’s one problem! Ok, there are more, which we’ll talk about later, but what about when the batter swings? In many cases, the pitcher might use a pitch to induce swings and get a weak ground ball or a pop-up. I’ve left that previous table up in the event you think, perhaps, that a batter’s swing decision shouldn’t factor in. But if you do, here is the same table, but only looking at pitches that didn’t garner a swing:

Before going any further, let’s hit some caveats:

1. This is fairly rudimentary, and there’s the possibility that pitches were marked in the wrong zone by Statcast. It’s also not broken down by pitch type. We might find that a pitcher seeks swings with one pitch in an area while aiming for a called strike in the same spot with a different pitch. This isn’t and cannot be a definitive analysis.
2. Kyle Wright and Bryse Wilson were included, but their pitch samples are relatively small. Neither has pitched much in the majors, and there’s no telling if their pitch rates have stabilized yet. If similar minor league data were available, I’d have included it. But for now, this is what we’ve got. It paints a picture, even if that picture looks a bit impressionistic next to the larger samples.
3. Pitchers can change! The pitch sample is from 2018-2019, but it’s not uncommon for a pitcher to change the way he uses a particular pitch between or even during seasons.
4. There are other aspects to catching. It’s not unreasonable to think one catcher might have a better rapport with a particular pitcher, making him a better choice to keep the pitcher comfortable and call an optimal game.

I’m sure there are more, and you probably intuited many of these as you read. But now that we’ve got the caveats out of the way, let’s look back at those results and apply them to the rotation!

Mike Soroka: Maple Maddux enjoys the greatest advantage from stolen called strikes (+1.2 calls per 100 pitches), so it would behoove the Braves to pair up Soroka and Flowers as much as possible. This checks out with past results as well. Soroka has allowed a career .245/.294/.355 line with Flowers behind the plate.

Max Fried: While it’s important to note that every pitcher gets more framing help from Flowers than d’Arnaud, Max Fried gets the least. Not only that, Fried and Flowers have never really enjoyed a ton of success together as a battery, allowing a .295/.351/.445 line together. If ever there was an obvious choice for a pitcher to keep Travis d’Arnaud as his personal catcher, it sure looks like Fried is the strongest candidate.

Mike Foltynewicz: As you can see, Folty sits near the middle of the table, making him a fine choice as a flex option of sorts. With Flowers, he carries a .250/.315/.420 line, which is slightly better than his career rates, but not by a lot. If it’s a day when one catcher happens to match up better with the opposing pitcher or park, or another catcher could use an extra day of rest, Folty’s turn through the rotation would seemingly be an excellent chance to have some flexibility in the rotation. In the context of the rotation, however, Folty might wind up throwing to Tyler Flowers more often than not. Newcomb, Fried, and Hamels all project to get less from Flowers’s framing than Folty would, and if they’re all in the rotation, it probably makes more sense to keep Flowers as Folty’s personal catcher. If it’s rookies, or Felix Hernandez, however, that might not be the case. Also worth mentioning is Foltenewicz’s comfort level on the mound. Given his bouts with controlling his emotions, it might benefit him to have more continuity behind the plate.

Cole Hamels: When Hamels returns, we should have a good idea of who he’ll replace in the rotation. If it’s Felix Hernandez, Kyle Wright, or Bryse Wilson, with Newcomb remaining in the rotation, it probably makes more sense to let Hamels be the catcher flex option going forward. If Newcomb seems bound for the ‘pen, on the other hand, Hamels would probably be better off paired with Travis d’Arnaud.

Sean Newcomb: Newcomb should get more help from Flowers than Fried, but only by a little. When Newk is in the rotation, it’s a fairly easy choice. Pair him with Travis d’Arnaud. Newk shouldn’t miss Flowers too much: he’s allowed a .240/.341/.412 career line when pitching to Flowers, allowing an OPS 11% worse than with other faces behind the mask.

Felix Hernandez: As you can see in the first table, Felix throws to Flowers’s hot zones more than any other pitcher. As you can see in the second, however, Felix gets enough swings on those pitches to drop him behind Soroka when it comes to projecting advantage from a great framer. That’s still enough to recommend pairing Felix with Flowers, particularly if Felix is determined to sinkerball his way to success. If that’s the case, and the King relies on the same pitch mix that led to terrible results, the pairing probably won’t last for long, as the King will be DFA’d or sent to the bullpen. Here’s hoping Flowers is instead framing cutters from a re-tooled legend for strikes in 2020.

Kyle Wright & Bryse Wilson: As mentioned earlier, the available sample for both is awfully small, so it’s hard to draw any concrete conclusions. That said, both trend toward the middle of the table; both get a solid benefit from Tyler Flowers’s framing skills, but not to a drastic degree. Wilson seems to hammer that low-mid zone the most without generating swings, so he’d get the edge for me, but the Braves could keep both as flex options for the catchers.

How would that look to open the season? Using Roster Resource’s depth chart, we have:

1. Mike Soroka & Tyler Flowers
2. Max Fried & Travis d’Arnaud
3. Mike Foltynewicz & Tyler Flowers
4. Sean Newcomb & Travis d’Arnaud
5. Felix Hernandez & Tyler Flowers

That actually sets up somewhat beautifully for keeping both catchers well-rested, if that’s the direction the Braves want to go.

To conclude things, I will re-iterate that I don’t really think catching platoons are this cut and dry. Players are going to have aches and pains. There will be late night extra inning affairs followed by 1 PM next-day first pitches. Cole Hamels will come back, others could hit the IL, or some young guns could force their way into the rotation. Ian Anderson could announce his arrival. There are going to be hot hands, cold bats, and matchup preferences. Also, in the event of injury, you want all your pitchers to at least have enough familiarity to feel comfortable throwing to either catcher. If, however, the Braves are looking for a general platoon framework for two players with similar batting profiles, this one might make sense. They have one of the best framers in baseball, and if he’s only going to play 110 or so games, they might as well get as much out of that elite tool as they can, and this could be the way.