There is something pretty simple about identifying your best pitch and deciding you’re just going to throw the ever living fuck out of it and see what happens. Most pitchers have decided they need a mix to get through a lineup two or three times. Then there are pitchers like Patrick Corbin, who stand out on a rock and say things like, “I throw a goddamn slider half the time and I dare you to do anything about it.”
The past two seasons, which just so happened to be the last two seasons before free agency for Corbin in Arizona, he decided that’s what he was going to do. Only two pitchers threw more sliders than Corbin in 2017, and only Jhoulys Chacin threw more last year. You could understand why, as according to FanGraphs it was the most valuable slider in the game. When toting that kind of weapon, it’s probably best you use it as much as you can, especially when you’re eying a contract with nine-digits on it, as Corbin got from the Nationals.
The scary thing for the Nats, or maybe it should have been, is that pitchers that lean that hard on a slider don’t tend to do very well long-term. Last year the top slider-throwers were Chacin, Corbin, Luis Severino, Jakob Junis, and Jon Gray. Chacin and Junis have ERAs over 5.00 this year, and Severino has yet to throw a pitch thanks to a lat strain. Only Gray has improved on what he did last year, and only marginally really.
In 2017, the top slider-throwers were Chris Archer, Corbin, Jason Hammel, John Lackey, and Ervin Santana. Archer has backed up since, and you don’t need me to tell you what happened to the other three.
The year previous, Madison Bumgarner made his way into the top five as far as throwing a slider, and then 2017 was the first year he ever got hurt and ended up missing about half the season. Same goes for Michael Pineda. It’s a very hard pitch to maintain its sharpness over multiple years and also your health. This is the needle that Corbin is trying to thread.
It would appear Corbin is somewhat aware of this, as he’s backed off of it a bit, throwing it 5% less than last year and replacing it with more fastball usage. It seems to have cost him some strikeouts and increased his walks, but he’s still got an ERA and FIP under 4.00. He’ll be hard-pressed to ever match the 11 K/9 that he put up last year, and if that’s what the Nationals thought they were paying for, well that’s on them.
The thing is, Corbin’s slider is getting more movement, both down and across the zone, than it did last year:
So he might be better off just riding and dying with it, whenever that might be.
That doesn’t make his signing any less weird. Yes, the Nationals definitely had a hole in the rotation after Scherzer and Strasburg, and you wouldn’t want any part of this in a playoff series. But does that matter if you’re not getting to the playoff series? The Nationals have a pretty middling offense–partly due to the growing pains of Victor Robles and Juan Soto–and a woeful bullpen. They also have an overmatched manager. Was another starter really highest on the shopping list?
It’s definitely a Cerberus of a top of a rotation. It’s just a wonder if that’s worth it when it’s getting you 80 wins.