Blake Treinen will be the Nationals closer.
Anyone saying it's a bad choice isn't thinking. Anyone saying it's the optimal choice isn't thinking enough. Not unless the rules have changed and things have gotten weird.
The past two seasons paint a very accurate picture of Treinen.We focus a lot on him turning a corner last year, but in a basic macro sense, Blake was good in 2015 too. He
had the better season in 2016, no doubt, but if you wanted to argue
that was mostly a product of BABIP luck I'd listen.
He's an extreme GB pitcher, at 64.2% over the past 2 years. That's good enough for 5th highest behind very effective relievers like Zach Britton, Brad Zeigler and Sam Dyson. As one would expect he doesn't give up a lot of home runs (very few GB HRs). He doesn't strike out a ton,* but he strikes out enough, about 8.5 per 9 innings, to be effective. His Achilles heel is that he does walk more than his share, over 4 per 9 innings, one of the worst rates for pitchers who have thrown at least 100 innings in the past 2 years combined. (301st out of 314 if I'm counting right). The overall picture is one of an rather effective reliever with one major, but not fatal, flaw.
Can Blake handle the 9th? I assume so. He did have issues in pressure situations in 2015. Terrible issues. Opposing hitters hit .310 / .390 / .423 in high leverage situations as opposed to .215 / .292 / .292 in low leverage ones. Translation : he racked up his good stats in unimportant situations. But in 2016 he was great in high leverage situations .194 / .282 / .306. So it's hard to say we should still worry about it. Both of these are based off relatively small samples so with no consistency between years you kind of have to throw up your hands and say he'll do as well in pressure as he'll do otherwise.
You do lose something by not having Blake and his GB inducing sinker come in to get a DP when necessary but if instead you are getting a strikeout from Kelley or Blanton, it'll be fine. The issue is less about the GBs here than about what replaces that and what replaces it should be good.
This would be a fine pitcher to hand your designated #1 reliever role to, if you didn't have someone better. However, as we discussed before, the Nats do. Shawn Kelley is demonstrably better. The story suggests there may be some questions about durability, though, that hold him back. OK then but Joe Blanton is demonstrably better too, with his higher strikeout rate and much lower walk-rate. Perhaps though they don't want to anoint a guy who is likely here for one year. And I haven't even mentioned yet, Koda Glover who could also be better but is young enough that legitimate questions linger.
Is this a problem, not using your best pitcher in the closer role? Certainly if you have a BAD pitcher back there it is, but that isn't the case here. You have a good pitcher as your closer. That's good. The question will be how they use the rest of the staff. The more regimented their roles the worse this decision is. You see you want to use your best pitchers in the most important situations. The most important situations do not happen at the same time every game. If you are flexible in your usage of your pitchers to combat these situations as they come up in the 6th-8th then there could be benefit from putting your 3rd best, but still good, arm as closer. If, however, you set everyone else up in roles, that benefit is diminished because you will see more important situations in the 9th than the 8th than the 7th etc etc. So for a robot just following "one pitcher per inning, have to have the same guy pitch in the same inning each game" rules, using your best pitcher as closer is actually best.
We'll have to wait and see what Dusty does. It's likely, I think, that he does choose a set-up man, but leaves the 6th-7th open. Given that any two of the three other pitchers available out of Glover, Blanton, and Kelley are likely to be good, I can see this being fine. The worst possible follow-up would be to put Glover in the 8th and now you could be manning the 8th and 9th with the 3rd and 4th best arms in the pen. All in all it's not terrible - 4 good arms used anywhere in the last few innings will be good - but again non-optimal.
If there's a true downside to this move it'll be something we uncover as the season goes on and it'll be related to the defense of the Nats. If Turner is a step down from Espinosa, if literally butt-hurt Murphy can't move like he used to (which wasn't great to begin with), if Zimm continues his aged decline (or worse, the Nats are forced to used Lind at 1B) these are all things that could effect the GB defense of the Nats negatively. Since Treinen relies heavily on GB defense this could impact him more than anyone turning former outs into hits, former DPs into forceouts, and situations he got out of in 2016 into trouble in 2017. But we don't know that yet.
This isn't the best move, but it doesn't mean it's a bad one. The Nats had several decent options and they picked one. Let's see what happens.
*this is what makes Britton special