What happened to Roberto Osuna?

Editor’s note: Since Roberto Osuna came to the Astros last July, we at TCB have had a certain reticence writing about him, for reasons known to all of you. But Osuna, like it or not, is the closer for the Houston Astros, and therefore an important component of the team. This article is an examination of his performance on the field, and is not intended as an endorsement of his off-field behavior.

I’m mad as hell, and I’m not going to take it anymore.

Troy Taormina-USA TODAY Sports

At opposing batters that is.

Roberto Osuna started 2019 on cruise control. His picture was in the dictionary next to the word “shutdown closer.” (OK, Webster’s doesn’t carry that word) From March 28th until May 20th, Osuna pitched 21.1 innings and allowed only seven hits and one run. He had a perfect save record, recording twelve. His ERA was 0.42, although his xFIP was a little less rosy; 3.72. Regression was due.

And then it happened. He started getting bombed.

In three games between May 24th and May 27th, Osuna surrendered five earned runs in three innings, including three home runs. From May 24th through June 23rd, in 10.2 innings, Osuna allowed eight runs, fifteen hits, with an ERA of 5.91. xFIP remained pretty steady at 3.99.

If xFIP is an eventual predictor of ERA, is 4.00 good enough for a closer? No.

Since June 23rd Roberto Osuna has become a different pitcher from any other known variety of Roberto Osuna from his entire career. Although so far, this has been a very effective transformation, it is too soon to say if it will remain so, or even that he won’t eventually revert to old patterns.

But whether or not it works in the long run, the change is sudden and dramatic. In the last five games he has upped his usage of the fastball 25%, increased his fastball velocity 1.6 MPH, and has almost eliminated the cutter, a pitch he used as much as the slider and change up.

He’s pitchin mad.

The Stats

Let’s look at a chart of Osuna’s pitch usage, fastball velocity, and slider velocity for his career up to 2019, 2019 up to June 23rd, and since June 28th.

In summary, Osuna’s fastball in the last five games has been about 2 ¹⁄₂ MPH faster than career average, and has jumped 1.6 from the earlier part of the season. He’s throwing it harder, and more often. Slider velocity has increased 2 MPH since the beginning of the season as well.

Just for comparison, Josh James’ fastball career average is 97.5, and his slider is 84.6. Did you know that Roberto Osuna is now a harder thrower than Josh James? Not when the season started.

Osuna’s pitch profile always seemed strange for a closer. Most closers have two hot pitches, maybe a third now and then just for fun. But Osuna had a four pitch arsenal he could command, more like a starting pitcher. He seems to be moving closer to a typical closer profile.

The above statistics come from Fangraphs. Brooks baseball adds some more details and a little more insight.

Fangraph charts do not distinguish between sinkers and four-seamers. But according to Brooks Baseball, Osuna used a sinker on occasion and since June 23rd has dropped its use.

Since June 28th

So according to Brooks Baseball, Osuna has made an adjustment that other Astros pitchers have made; he has abandoned the sinker. And with good reason, because it was getting crushed.

Not as easy to explain the reduced use of the cutter, which was effective according to this Brooks data, and according to Fangraphs had a very high pitch value of 3.92/C before June 28th. (0 being average)

Brooks and Fangraphs seem to disagree as to how often Osuna threw a cutter, Brooks apparently classifying as cutter some of the pitches Fangraphs called sliders. If we use Brooks’ definitions, we must modify the thesis from almost eliminating the cutter, to greatly reducing the use of the breaking ball in general. In either case we see a definite change in approach.

Is the New Osuna a good thing?

That an Astros pitcher would change his pitch selection is no huge surprise. To me, the most intriguing question is: Where did Osuna get this extra gas on his fastball and slider? Must be pine tar.

How is the new Osuna doin?

In a small sample size of five innings purdy good. No runs, one hit, six Ks, two walks, but the xFIP is still in the same range as before, 3.57. Furthermore, his BABIP during this time is a paltry .100, and even though 80% of the batted balls against him have been either fly balls or line drives, none of them have been home runs. But that 80% number is a little troubling if it holds.

So is the new Osuna same as the old one?

Time will tell.