Andrew Cashner’s new approach is the key to his success

The Red Sox made their first — and possibly last — move of the trade season over the weekend when they dealt a pair of DSL prospects for Andrew Cashner. As I wrote on Monday, the trade signifies the continued importance of the rest of the rotation that’s been here all year. Dave Dombrowski essentially acknowledged as much with this deal.

That being said, I don’t really want that to come off as overly dismissive of Cashner as a pitcher. The former Orioles righty is a clear upgrade over what they’ve been trotting out in the fifth spot of their rotation. He’s an actual, major-league quality starting pitcher. That probably sounds dismissive and like an extremely low bar, but in today’s game it really isn’t. There aren’t a ton of actual major-league starters right now! The Red Sox didn’t just pick a starter out of a hat. Clearly, there is something they liked about Cashner and a reason he specifically was their target.

Boston wanted him to fill a very specific role, and that’s exactly what he’s going to do. At least, it is based on what he’s done so far this year. A lot of Cashner’s recent seasons have been subpar — three of his last five seasons have been below replacement level according to Baseball Prospectus’ DRA-based WARP — but he’s pitching well this year. The righty has a 3.83 ERA, a 4.24 FIP and a 4.62 DRA on the season. There’s an expectation based on those numbers that he’s going to regress off that ERA as the year goes on, but even if he gets closer to his current peripherals he’d still be a league-average pitcher at worst. A league-average arm who can go six innings per outing is more than worthy of the number five spot in a rotation.

Photo by Billie Weiss/Boston Red Sox/Getty Images

This is a big change from the guy the Orioles got in 2018, Cashner’s first year in their organization. Last year, he finished his season with a 5.29 ERA, a 5.36 FIP and a 6.69 DRA. He was, by any measure, extremely bad. This season, he is striking out more batters (though still misses bats at a rate much worse than league-average), is walking fewer batters and getting more ground balls. To put it more simply, he’s improved in just about every way imaginable.

If you’re looking for optimism about his changes — and really, who isn’t looking for any bit of optimism onto which we can latch with this Red Sox team? — you are in some luck. This is not just a fluky improvement from Cashner that could dissipate at a moment’s notice. I mean, that is always a possibility but at least in his case there are legitimate changes at which we can point as causes for his improvement. Specifically, the righty has made some major shifts in his arsenal that have turned him into a different pitcher.

The biggest and most obvious change, and the one you will hear about a ton over his first few starts with the team, is that he has almost entirely ditched his sinker. According to Statcast data, Cashner threw this pitch just under 35 percent of the time last year to make it his most used offering. The results on it were terrible, too. Statcast had the expected wOBA on the sinker at .398. wOBA is on the same scale as OBP, so, yeah. Not great. It also only got whiffs 6.6 percent of swings. Again, that is terrible. Clearly, ditching it after that performance has to at least be a thought, and sure enough he’s thrown it only 3.7 percent of the time in 2019.

So, that alone has made a big difference. Still, when you are moving away from a pitch that was such a big part of the repertoire in the previous year, obviously another offering has to take its place. Unsurprisingly, part of that increase has gone to the four-seam fastball. He’s almost doubled his usage rate on that pitch from 26 to 47 percent from last year to this year. It hasn’t really been a great pitch for him with an expected wOBA of .378, but he’s getting some whiffs (17 percent) and it’s been a tablesetter for the righty early in counts.

Photo by G Fiume/Getty Images

The real difference for Cashner, though, beyond the ditching of the sinker and beyond the increased four-seam usage, is his changeup. In 2018, he used that pitch just 13 percent of the time. This year, he’s doubled that usage and also improved its effectiveness. It was a solid weapon for him in the past, but with some tweaks it’s become his best weapon with a .280 expected wOBA and a 29 percent whiff rate. The result has been eye-popping numbers against lefties, who have hit just .182/.249/.250 against him this year. Righties have actually been pretty good against Cashner this year, but he’s been able to get results because that changeup has been death against lefties.

At the end of the day, no one really should be expecting the world from Cashner with the Red Sox. He is a good, solid addition who will help the team but he is not a superstar. That’s not what the Red Sox need, though. Instead, they need a solid pitcher who will give them stability and length from a position where that’s severely lacked. In the past, that has been far from a guarantee for the righty. Nothing is a guarantee in the future either, of course, but with a new arsenal that has watched Cashner ditch his sinker and emphasize a devastating changeup there is at least plenty of room for optimism.