Thanks to an intervening offseason full of storylines, both exciting and frustrating, it feels like ages ago that the Chicago Cubs signed Tyler Chatwood to a three-year, $38 million deal. For like a month, it was the biggest transaction of the offseason, and, until the Cubs signed Yu Darvish a couple weeks ago, it was the biggest starting pitcher signing of the whole offseason. (Yes, that’s right, it’s still the second largest starting pitcher deal signed this offseason!)

At the time the signing went down, we dug into a whole lot on Tyler Chatwood (see here and here for initial thoughts), but it’s been a while since we looked at something interestingly Chatwood-specific.

Recently, Kyle Hendricks, a former high school travel team teammate of Chatwood’s, said something to Cubs.com that stuck out, and got me thinking: “The more you pitch there [Coors Field], you find different things. Talking to [Chatwood] is kind of funny, too, since he pitched there so much. He has a good curveball and spin rate on his curveball, and in Colorado, it’s hard to throw curveballs. You feel you try to throw harder and it stays up and doesn’t spin. That could be a big difference for him coming here, just feeling comfortable with everything.”

Chatwood, curveball, spin rate, Colorado. Like I said, it got me thinking.

While we’ve covered Chatwood’s significant home/road splits in greater detail before, we haven’t really dug into the effect it had on his curveball, specifically, or, more simply, his curveball’s effectiveness in general. It’s something Chatwood, himself, has spoken about, telling Sahadev Sharma, “I feel like the tough part is that once you figure out what your breaking ball is in Colorado, when you leave it’s a completely different pitch. You have a lot more bite and you have to raise your eyes a lot more on the road. I always say I’m going to use it more. It’s always been my best pitch since I was young, my best breaking pitch. But it’s tough when you have to constantly change how you use it.”

One of Chatwood’s calling cards is his elite spin rate, and, given that he can single-handedly take this rotation from good to great (you’re only as strong as your weakest link and whatnot) his curveball deserves a little more attention.

In 2016, Chatwood (coming off a year entirely missed because of his second career Tommy John surgery) threw his curveball just 4.9% of the time, at 77.6 MPH, and with an average spin rate of 2,887 RPM (6th best in MLB for pitchers with at least 100 curveballs thrown). Despite an obviously-still-elite spin-rate, the value of his curveball was still just -3.1 (not particularly inspiring, right?).

Well, in 2017, when Chatwood was another year removed from Tommy John surgery, he more than doubled his curveball’s usage (11.1%), while throwing it more than two miles per hour faster (79.8 MPH), and with an even more elite spin rate (2,981 RPM, 5th in MLB) than he had the year prior. With two extra notches on the radar gun and an extra 100 RPM, the value of Chatwood’s curveball spiked to +2.4 (one of the top 25 curveballs in baseball) – and that’s all without considering any of that ballpark stuff.

In other words, despite still playing half his games at Coors Field (something he won’t have to do this year), where he was constantly having to readjust the way he threw the curveball, Chatwood was still able to increase its effectiveness by throwing it harder and spinning it more (a product of better health and another year away from TJS, if I had to guess).

If in 2018, he’s able to continue this trend in velocity and spin rate leaderboards, there’s a chance this pitch could take another step forward and become one of the most valuable curveballs in baseball – especially if he’s able to confidently work it in more than he has in the past, thanks to a more consistent pitching environment.

Now, there’s one strange caveat to all of this, for which I don’t really have an answer. It’s all about something you’re probably asking right now: so, if it’s hard to throw a good curveball in Colorado, his curveball must have been clearly more valuable on the road, right?

Well, here’s the thing. Despite the fact that we more or less know that what Chatwood and Hendricks say about Coors Field is true, Chatwood did actually have a bit more success with his curveball *at home last season* (whiff rate against his curveball was higher and the slugging against it was lower). Yet, in 2016, the exact opposite was true of his curveball at home (the whiff rate was lower and the slugging against was higher). I don’t have much of an explanation, but I think the fact that he was regaining his feel for the pitch (spin rate and velocity) after TJS probably played some sort of role, as well as the fact that having to change the pitch at home and on the road could lead to weird inconsistencies, even if – in small-ish samples – they run counter to what you might expect.

In any case, I think it’s pretty to easy to spot a trend: last season, a healthier Chatwood was able to throw his curveball more often, with greater speed, and with a higher spin rate. Because of that, the pitch was much more successful overall, and that seems like the sort of progress he can carry into 2018 both naturally (further removed from Tommy John surgery) and artificially (fewer games at Coors Field, and then switching to a totally different environment in the next start).

Oh, also: the guy just turned 28 in December, nine days after Hendricks turned the same age. He’s plenty young enough for these kinds of things to still be settling into place.

Brett Taylor contributed to this post.