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Rockies pitcher Jon Gray is having the best and worst season of his career

What you think of Jon Gray’s 2018 season depends on the question you’re asking

Jon Gray is having the best season of his career.

For one, he’s posting the best strikeout and walk numbers since breaking into the majors. The concept of an “ace” is slippery, but if forced to pick out a couple stats that reflect ace-dom, I might go with a lot of strikeouts and not a lot of walks. That’s Gray so far in 2018. In 6123 innings across 11 starts — about a third of a season — Gray has a struck out more than 10 batters per nine innings and walked fewer than three. It’s been good for a 4.44 strikeout to walk ratio!

Now, it hasn’t been perfect. Gray has given up a lot of hits, a lot of runs, and more home runs on a rate basis than usual. He’s been a little unlucky overall, as a lot of the balls in play hit against him have fallen for hits, and his strand rate isn’t as good as it usually is.

Whatever though. In order to really truly understand how great Jon Gray has been, we should consider all the contextual factors that have contributed to his season — quality of opponent, home/road splits, pitch selection, and, returning to our earlier theme, whether or not he should have struck out more guys than he has and walked even fewer.

Lucky for us, there’s a stat that takes all that into account. Baseball Prospectus’s Deserved Run Average (DRA), which is scaled to look like ERA, is an incredible 2.08. That’s Noah Syndergaard territory. What that says is that Gray has been much better than his results indicate.

To further make the case, DRA is the building block of BP’s Pitcher Wins Above Replacement Player (PWARP). In 2016, Gray’s PWARP was 2.0 in 168 innings. He improved in 2017 with a higher PWARP (2.3) in fewer innings (11013). In 2018, Gray has already accrued 2.1 PWARP, and he’s done so in just 6113 innings pitched! Truly, Jon Gray is having the best season of his career.

★ ★ ★

Jon Gray is having the worst season of his career.

Sure, we have to discount his 40 inning debut in 2015 to make that statement, but that doesn’t make it less true. Gray’s 26 years-old now, and he should be smoothing out his rough edges on the way to becoming the best starting pitcher on staff. Instead, he’s just been so damn hittable.

Sure, Gray does have an excellent strikeout ratio. He’s K’d 10.4 batters per nine innings. But he’s also allowed 10.4 hits per nine innings. Gray’s strikeouts aren’t compensating for the rough time he’s had with that really important part of pitching, preventing runs. In a world of complicated ways of viewing baseball outcomes, the simplest method of evaluation is telling us something we don’t want to hear about Gray.

Unfortunately for us, there’s a stat that captures the simplicity of runs allowed. RA9 is ERA without the “earned” part — runs allowed per nine innings. If this seems strange, it may only be because we’re so used to displacing all of the responsibility away from pitchers for some outcomes, judged by the scorer, for which the pitcher is only partially responsible. That’s the “unearned run” concept that forms ERA, and it doesn’t make a ton of sense when breaking it down. RA9 eliminates the gray area to describe something simple and unambiguous.

RA9 is also the building block for Baseball Reference’s Wins Above Replacement model for pitchers. Gray’s RA9 so far this season is 5.55 — not great. His Baseball Reference WAR isn’t great either, as the 0.5 WAR he’s put up so far indicates he’s had a below-average first third of the season. Below average is not where the Rockies want Gray to be. Truly, he’s having the worst season of his career.

★ ★ ★

Jon Gray is having the weirdest season of his career.

What do you make of a pitcher who’s doing all the process things right — the things that contribute to a pitcher’s success — but isn’t getting good results? The Rockies may be asking that question right now. If someone had told me before the season that Gray would increase his strikeouts and reduce his walks, I would immediately assume that he’s having the best season of his career. Similarly though, if someone told me that Gray is giving up more home runs and hits on a rate basis and has been giving up more than five runs per nine innings, I’d start using phrases like “step back” and think that he’s probably having the worst season of his career. Both of those things have turned out to be true.

There’s a pitching stat that exemplifies this confounding season. FanGraphs’ Wins Above Replacement for pitchers is based on FIP, and FIP is based on strikeouts, walks, and home runs allowed, the three things the pitcher is supposedly able to have the most control over. It’s designed to be an alternative ERA that can be useful to estimate future expectations. Gray’s FIP in 2017 is about the same as it was last year, 3.18 to 3.16. The increase in strikeouts and reduction of walks seems to be balanced out by giving up a few more home runs.

Still, it’s a good mark that should mitigate some concern. And yet, that concern is based on the fact that Gray’s giving up a lot more runs than usual. It all amounts to a FanGraphs WAR of 1.6, which is really good. In fact, it’s the sixth best in the National League. I’d wager that if you asked Gray, he would say he doesn’t feel like he’s been a top 10 pitcher in the NL. Rockies fans would likely agree.

Jon Gray is truly having the weirdest season of his career.

★ ★ ★

This isn’t an argument against WAR. Instead, it’s an argument to understand what each one is saying. As ESPN’s Sam Miller brilliantly put it put it, Baseball Reference has the “what happened” WAR measure, FanGraphs is the “what should have happened” look, and Baseball Prospectus owns the “what should have should have happened” view.

In my view, WAR is most useful and interesting as a descriptive statistic, and the simple elegance of RA9 captures that perfectly. Gray really is having the worst season of his career.

So far, at least. That’s where the value of what goes into the other measures come into play. Gray has experienced bad results — that’s obvious. But that doesn’t necessarily mean he’s been pitching poorly. He could become one of the best pitcher in the National League without really changing anything.

We know what has happened with Gray, and we have a pretty good idea of what should have happened, as well as what should have should have happened. As far as what will happen, there’s no stat for that. Thank goodness.