What did the Rays gain with The Opener?

Baseball is really a very simple game. One man throws a ball. Another tries to hit it. If the hitter succeeds, eight new men come into play as they try to catch the ball.

While fielders are important, and a great fielder is fun to watch, the central matchup in baseball is between the pitcher and the hitter. Getting an advantager in this matchup is one of the primary jobs of the manager.

The Angels, especially when Shohei Ohtani is not slated to bat, are a team of right-handed hitters. One of them is great (Mike Trout), one of them was great (Albert Pujols), at least one is very good (Justin Upton), and a few more are maybe good (Andrelton Simmons, Zack Cozart, Ian Kinsler, and Jefry Marte). All of these Angels hitters, as well as some others of lesser offensive note, are righties.

To oppose that lineup in games three and four of this past four-game series, the Rays had three pitchers available who can go varrying degrees of long: a rookie lefty without much prospect buzz but with good command (Ryan Yarbrough); a rookie lefty prospect with good stuff but a penchant for wildness (Anthony Banda); a veteran righty swingman whose best pitch is a devastating changeup that’s made him less effective against righties than he’s been against lefties (Matt Andriese).

Now pick two of them. Who do you want facing all those Angels righties, including arguably the best baseball player ever, when they’re stacked at the top of the lineup in an order of their choosing?

Oh wait, there’s another option. You also have Sergio Romo, a veteran closer with World Series experience, who throws one of the best sliders in the game, which he can sweep across and off the plate to righties.

If your answer is that you want to use your tough righty reliever to face their best righties now, rather than to save him for a hypothetical high-leverage situation that may never arise, you’ve made the same choice as the Rays.

You don’t really need fancy numbers to see why this choice makes sense, but if you want fancy numbers, read on.

When analyzing matchups, I like to use regressed platoon splits. They’re a way of combining what we’ve seen players do and what we know other players like them are likely to do. My version of regressed platoon splits is based on the work of Bojan Koprivica, and combines that with the FanGraphs Depth Charts projections for hitters, and some simple regression projections for pitchers. You’ll see similar numbers used by Jason Hanselman over at The Process Report. That’s not a coincidence.

All numbers are in wOBA. Averages are in a neutral park. Matchups are set to the park factor for Angel Stadium.

First off, here are the options that the Rays had available, with a few of their projections.

Caveats. My simple pitching projections don’t deal with aging especially well, so Romo is probably not actually this good. Also, Banda’s shown an extremely wide split in limited major league time—wide enough to show up even against the regression—but I’d be cautious in saying that that’s true talent.

Still, the point that Sergio Romo is a significantly better option to face tough right-handed batters is clear. By these numbers he’s 14% harder for RHB than is the average righty. He destroys them. Which is what you should expect from someone with a slider like that.

Now here’s the matchups manager Kevin Cash and the Rays were working through.

This table is sortable, so go ahead and sort it by which game you wish to consider.

In game three of the series, Romo struck out Cozart, Trout, and Upton before turning things over to Yarbrough. That meant that Yarbrough could work into the eighth inning (going 6.1 innings) while only facing Trout and Upton twice. Those two were by far the two most dangerous hitters for him in the lineup. Trout did double off Yarbrough, but the Rays were able to work around that. The only run Yarbrough gave up was due to an Ian Kinsler double, which happened in Kinsler’s third time seeing Yarbrough (that dangerous thing to give a hitter, which the Rays did not give Trout and Upton).

Sometimes the matchups line up the way your team wants them to, and it still doesn’t work out. In this game the Rays got the matchups they wanted, and it played to script.

In game four of the series, Romo walked Kinsler to lead off the game, but then once more struck out Trout and Upton, and got out of the inning with a groundout to Simmons. Fantastic, once again.

The second inning was where the decision making got interesting. Marte is a dangerous hitter against left-handed pitchers. Him due up was a good reason not to bring in Banda immediately. But the question here is Andriese vs. Romo. Cash elected to leave his matchup righty in to face the platoon bat of Marte. Romo struggled to find the zone, walking Cozart, but then struck out Marte. With their two splits combined, that was the expected result Cash was looking for. Only then did he bring in Andriese, who got out of the inning cleanly.

Unfortunately, the script didn’t play out for the Rays after that. After a scoreless third in which he pitched around Trout, Andriese committed an error in the fourth to allow a leadoff baserunner, creating a mess that Jose Alvarado was unable to clean up (righty Chaz Roe might have been the better option to try, but he’s been worked hard over the past few games). Trout did Trout things in the fifth, creating offense with his eye and his speed, and by the time Banda came in, the Rays were two runs behind. The runs he gave up (and I emphasize that this was a tough matchup for the young lefty, so giving up runs was not unexpected) did not matter for the outcome.

Conclusion

Baseball is a game of matchups. The Angels most dangerous hitters are Mike Trout and Justin Upton. Those two are especially dangerous against left-handed pitchers.

By starting Sergio Romo in games three and four, the Rays were able to neutralize the Angels’ big guns first time through the order, and to set up Ryan Yarbrough, Matt Andriese, and Anthony Banda with a better chance to succeed. In game three, everything worked perfectly. In game four, it worked pretty well too, but the Rays lost anyway. That’s baseball.

The Rays have done this before with Andrew Kittredge. They will do this again, probably both with Romo, and with the lefty Jonny Venters. It’s a strategy that makes sense, given the right situation.