NEWSLETTER
Late last Friday night, Jake Arrieta made his 10th start of the season, and it was something of a mixed bag.
On the one hand, Arrieta allowed just 5 hits and one walk through six innings and struck out nine batters on a fantastic 15 whiffs – a usually devastating collection of underlying statistics. But on the other hand, Arrieta took the loss after giving up two homers and, ultimately, four earned runs.
In a way, that one game is a perfect representation of Arrieta’s season as whole. Somehow, he’s accumulated abysmal results (4.92 ERA – 20th worst in MLB) while continuing to show strength in areas that tend to lead to good things (3.59 xFIP – 24th best in MLB). So how do we reconcile these differences?
Well, some of his issues are definitely (bad)luck-based – his strand rate, BABIP, and HR/FB ratio are WAY out of whack and are unlikely to stay that way. But some of his issues are definitely from the well, that’s his fault category – his ground ball rate, hard contact, and velocity are all out of whack, but are not necessarily likely to rebound.
So the best we can really do right now is continue to study the underlying statistics and trust that whichever direction they point is the direction things are likely to head. And to that end, we have two additional advanced metrics to add to the story.
Fortunately, both are painting Arrieta in a positive light (or, at least, more positive than what he’s earned so far). Here’s the first one:
A BPro reader suggested DRA had to be "wrong" because of Senzatela. Well, let's see what happens from May 28 to end of season. pic.twitter.com/mo9ALVbTGn
— Tangotiger (@tangotiger) May 29, 2017
Before I explain what’s going on here, let’s clear a few things up.
- Deserved Run Average (DRA) is a BP-created statistic that is similar to FIP. The idea behind DRA is to determine how well a pitcher pitches based solely on things he can control. In addition, DRA is park, platoon, framing, and opponent-adjusted, which means that the folks at BP are really trying to account for any external variables interfering with the data (that’s good!).
- DRA- is used to show how much better or worse than average a pitcher’s DRA is to the rest of the league. Like wRC+, a 100 DRA is average. Unlike wRC+, the lower the number the better.
- And here’s how MLB.com explains RA9: “RA9 is runs allowed per nine innings pitched – the title says it all. It’s basically ERA with the “E” removed.”
We good?
So, as you can see above, Jake Arrieta has allowed a really large 6.04 runs per nine innings this season (though remember, RA9 is going to be bigger than ERA because it counts unearned runs), despite boasting a Deserved Run Average of just 3.85. And to put that in further context, Arrieta’s 3.85 DRA is about 15% better than the average Major League pitcher. So right there, you can say DRA indicates Arrieta’s had some seriously bad luck with the number of runs that have scored in his outings.
But we (or rather @TangoTiger) took it a step further.
Same for @steamerpro. "ERA" is forecasted rest-of-season ERA/0.92 to convert to RA9 scale. "RA9" is RA9WAR converted to RA9. pic.twitter.com/nTe396w942
— Tangotiger (@tangotiger) May 29, 2017
Tango took the Steamer projected rest-of-season ERAs for these pitchers and adjusted it to the RA9 scale. By that measure, Arrieta projects to produce something around the 4.07 range. That’s not necessarily fantastic, but compared to Arrieta’s actual 6.04 RA9 so far this season, it’s dramatically better. So where does that leave us?
Well, unfortunately, nowhere … yet.
The numbers won’t definitively tell us that Arrieta’s going to be fine for the rest of the season – because, frankly, there’s always a chance that something we’ve missed completely is causing his vulnerabilities or he can always just flat out gets worse the rest of the way.
HOWEVER, the data does add more support to the theory that Arrieta is pitching better than his numbers have indicated so far. Or, another way to look at it if you prefer: it’s quite likely that some of things that are out of Arrieta’s control have plummeted at precisely the worst time (i.e. when he’s struggling with some of the things that are in his control). You can call it an excuse or me an Arrieta apologist, but that’s most likely what is going on: the dreaded combination of bad performance AND bad luck.
There are no guarantees in this game, but there are things that are more likely to happen than others. And from what I’ve seen here, in other advanced metrics, and with my own eyes, I’d say it’s more likely that Arrieta gets better results the rest of the way than he has thus far. And that’s something the Cubs desperately need.
He’ll try again today in San Diego.
