Logan Forsythe and Platoon Advances

Logan Forsythe came out of nowhere for the Rays last year. There he was: 28 years old and suddenly 15% better than he ever was before, in twice as much playing time as he’d ever had in a season, no less. There’s some power growth, some added patience, and some of the best batted ball luck and defensive numbers of his career. What part of this do we believe going forward?

To answer that question, we should probably try to find the source of that growth. That’ll help us suss the likelihood that the growth sticks.

The biggest jump in all of Forsythe’s peripherals comes on the splits page. Check out the right-hander’s weighted runs created plus numbers against right-handers over his career, from start to last year:

Yes, against lefties he had a 164 wRC+, and that seems like the more ridiculous number to look at than his more modest 108 wRC+ against righties, but there are a few reasons we should look closer at the number against righties. For one, the work against lefties was only his second-best of his career, and his career number (131) is also good.

And for another, right-handers are supposed to be worse against right-handers. The knock on Forsythe was that he might be a platoon utility infielder because he’d been so bad against righties so far. Then it finally all clicked and he was better than average for the first time against same-handed pitchers.

If that continues, he should be a decent player again next year. According to the numbers, you really want a large sample to believe in platoon splits. Using Matt Klaassen’s post on estimating platoon split by regressing against Tom Tango’s recommended samples, we can estimate his true talent platoon split.

He’s shown a huge 49% platoon spit between his wRC+ against lefties and righties. If you regress that against league average given his plate appearances against both, you get a 15% platoon split going forward. Given his 101 wRC+ projection, that means Forsythe should have a 93 wRC+ against righties and a 108 wRC+ against lefties.

That sort of production puts him within shouting distance of Brandon Phillips (97 wRC+ against righties last year) and Johnny Giavotella (96) last year. Over the last three years, Phillips has a 92 and Brian Dozier a 98 against righties. It’s good enough to play, maybe. Especially since he would be above-average against lefties (like a Danny Espinosa and his 112 wRC+ against lefties, sort of).

Do we have strategic reasons to believe in his improvement? Sure, he tightened his swing zone against righties. 2015 (right) looks better than 2014 (left), especially when it comes to pitches down out of the zone.

That’s allowed him to get better on the inside part of the plate and develop a hot zone this past season. He didn’t have a hot zone in 2014.

The projections for Forsythe next year peg him as a nice little player (.254/.327/.388) rather than the ninth-best second baseman in the league. That’s probably due to some batted ball regression more than anything. His platoon splits were probably too drastic in the past, though, and that’s where the good news come in. If he can keep his work against righties close to league average, he should probably have a job and the opportunity to show a little power and patience and speed. That’s more than you could have said going into last season, even if it’s not the most exciting thing to say about next season.