NEWSLETTER
Yesterday, the Washington Nationals were gifted a rainstorm that allowed them to reshuffle their rotation and go with one of the league’s best pitchers, Stephen Strasburg, against the Cubs in Game Four today instead of their fourth best starter, Tanner Roark.
But that’s not what they planned on doing.
Nope, the Nationals said they were sticking with originally scheduled programming – Roark – because Strasburg is sick from mold, or threw a bullpen session yesterday, or because Dusty Baker just likes attention or something.
And then – CRISSCROSS – there’s a report that Strasburg actually will be starting, which would likely leave Roark available instead in long relief. (Or maybe Strasburg isn’t starting. As of my 10th time editing this post, it’s not yet clear.)
Huge move by the Nationals? Terrible break for the Cubs? Sure, maybe. But Roark was probably a lot better than we were giving him credit for.
Roark is a 31-year-old right-hander who made 30 starts (181.1 IP) for the Nationals this season, earning a 4.67 ERA along the way. But before you get too excited about the elevated run allowance, I’ll point out that his 4.13 FIP is far better.
Indeed, Roark was relatively unlucky this year: his .300 BABIP is about twenty points higher than his career average, while his 66.3% strand rate is about nine percentage points lower than he’s used to seeing. Also in his favor, you’ll find a 48.2% ground ball rate, which is above both his career and the 2017 league average, and a 13.5% HR/FB ratio that’s right in line with the new juiced-ball league-norms.
So, basically, Roark is the poster child for why ERA doesn’t give you the whole story – he’s much better than the 4.67 ERA implies and he hasn’t been especially affected by the juiced-ball era because he gets plenty of weak contact and keeps the ball on the ground.
In fact, he’s been sufficiently good (behind the scenes) this year, Jeff Sullivan created a fun poll-based post to see how well you could tell him and his more widely-heralded Game Four opponent, Jake Arrieta, apart. You’ll be surprised to learn that in almost every meaningful stat here in 2017, these two are just decimals apart.
Even their lefty/righty splits are eerily similar:
Versus Lefties:
Jake Arrieta: .354 wOBA
Tanner Roark: .356 wOBA
Versus Righties:
Jake Arrieta: .266 wOBA
Tanner Roark: .268 wOBA
The one meaningful difference I can spot is that Arrieta’s 20.0% soft-hit rate this season is a clear step above Roark’s 16.7% mark. But even then, Arrieta has allowed more hard contact than Roark did this year.
As far as recency goes, Arrieta is still getting over a hamstring injury, whereas Roark posted a 3.90 ERA and 3.75 FIP in the second half, both very good marks. Arrieta posted a 2.28 ERA and won Pitcher of the Month honors in August in the second half, but also posted a 4.11 FIP.
But hey, let’s pump the brakes for a minute, because we’re missing one major thing, and it’s a significant part of the reason the Nats are still considering switching up the rotation.
Sure, Roark might be better than his ERA and even our expectations, but there’s still one thing he’s not: Stephen Strasburg. Roark is obviously a big part of a very talented rotation, but he’s still their fourth best guy, which means there’s three other pitchers the Nationals expect to perform better against the Cubs (all things equal).
In other words, if the Cubs were facing him today instead of Strasburg, that would be a win, even if you think the Cubs can handle Strasburg better a second-time around (especially if he’s all molded up). And here’s another thing: although Roark and Arrieta’s numbers have been similar this year, it’s not as though their ceilings are the same. When healthy, Arrieta is the superior pitcher, end of story. If he’s gotten enough time off from his hamstring soreness and pitches like he was before the injury in the second half, there’s really no contest in comparing the two.
So I guess, let’s hope Arrieta is feeling well, the Cubs knock Strasburg out early, and then maybe knock Roark around, too, if he comes in for long relief.
Brett Taylor contributed to this post.
