How much value is there in 23 2/3 awesome innings? Trevor Rosenthal tries to find out. They might be just enough to make him the best remaining free agent reliever on the market after Liam Hendriks joined the White Sox.
“But Alex Colomé and his 0.81 ERA,” you may say, and you may be right, although we are concerned about his falling strike rate. But whether Rosenthal actually or not is The best remaining free agent helper is less the point than the fact that it’s a statement we could even reasonably make because it wasn’t that long ago that Rosenthal wasn’t even considered on Big League Reliever. So the wrong things had gone.
A brief summary of Trevor Rosenthal’s experience for those who don’t know:
2012-17: Very successful St. Louis Reliever
2.99 ERA, 328 games, 3.04 strikeout-to-walk ratio
For six seasons with the Cardinals, Rosenthal was one of baseball’s best helpers. Only seven aid workers had more strikes in this six-year period; He made the All-Star Team in 2015. Despite some shoulder and control issues in 2016 that cost him his turnkey job, he was a big part of some successful St. Louis teams, particularly in the playoffs. In 23 postseason games for the Cardinals, Rosenthal allowed two deserved runs and scored 42 in 26 innings. Late in a 2017 season when he was hitting a career best (to date) of 37.6%, he injured his elbow and had to have an operation by Tommy John to keep him away from 2018.
2019: disaster
13.50 ERA, 0.65 strike-to-go ratio for three organizations
Rosenthal signed a one-year deal with the Nationals for 2019, but to say “it didn’t go well” is an understatement as he went 15 in 6 1/3 innings and was released in June. He caught the tigers but was released in August after eleven more walks in nine innings. The Yankees picked him up and sent him to the minors, where he got into a single triple-A game and ran three of the five batters he faced. Overall, it ran an impressive 30.9% of major league players, which is one of the highest annual rates since World War II.
2020: return to form
1.90 ERA, 23 games, 4.75 strikeout-to-walk ratio for Royals, Padres
After this performance, Rosenthal couldn’t even close a major league deal and signed with Kansas City as a non-cadre invitation to camp. He was added to the list after a strong spring training session and he was … amazing. Rosenthal made 14 games for Kansas City, scoring 21 while walking just seven. This was an accomplishment strong enough that the Padres traded it in for him as a stretch run supplement in August. In nine games for her, he beat 17 and passed one. On! A year after Rosenthal was unable to score enough hits to stay with the majors, he pitched high leverage innings for one of the best baseball teams.
Trevor Rosenthal, K’ing the Side. pic.twitter.com/TrjUiwqX64
– Rob Friedman (@PitchingNinja) October 3, 2020
All of this makes us … Where, exactly for 2021? We’ve all had so much to worry about the “small sample size” of 2020, what was and wasn’t important in a two month season, and the truth is, the answer isn’t one size fits all. It’s a case-by-case matter where we decided together that Trevor Bauer’s great 2020 matters – he’s going to get one far Larger contract than a failure in 2019 – but Christian Yelich’s failure in 2020 is nothing to worry about.
Most of the time we try to take past results – although Rosenthals were of course excellent – and bring them into the process. What went into these results? What things can we trust without them being replicated over an entire season? Was 2019 a coincidence or was 2020?
For pitchers, speed is the easiest to trust. You only need to see a few pitches to know that Aroldis is throwing Chapman hard and Kyle Hendricks is not. In Rosenthal’s case it was always throwing heat, and it still does. Last year, 650 pitchers threw at least 10 fastballs (four-seam, two-seam, or sinker) and only 8 of them had a higher average than Rosenthal’s 98.0 MPH.
As you can see on this monthly chart, that’s more or less in line with what he’s always been doing. (It’s not entirely difficult to see where his elbow started barking in 2017, as you can see.)
Because he had relied on his fastball about 2/3 of the time, and because it was so effective – an average of .154 and .212 against him – he came into the game as one of the truly elite four-sailors in the statcast run gauge, the the quality of the pitch as well as the frequency of its use combined.
You really should have two takeaways off this table. The first is that Rosenthal’s four-seater was incredibly effective in 2020, in a class with some of baseball’s biggest pitching names – Bauer, Buehler, deGrom, and Hendriks. The second could be, “Maybe we should pay more attention to Blake Taylor,” but that’s a completely different problem.
So we’re happy to say 2020 wasn’t a coincidence considering how good the underlying metrics are, and considering his track record with the Cardinals over the years. But what about 2019? What happens?
“It felt a little different at first,” Rosenthal told the Kansas City star last spring. “Then, as it got worse and worse, I felt strong. I felt that my speed was good. I noticed that I was cutting a lot with my move. My slider was way better than my fastball and my move, which is not normal. So those were some red flags that I saw early on. “
He wouldn’t be the first pitcher to have trouble throwing strikes after Tommy John’s operation. If you look at his zone rate – quite simply the percentage of seats thrown into the strike zone – on the fastball, you can see pretty clearly that 2019 didn’t start well and it got worse, just like he said.
The idea that command is the last thing that comes back after Tommy John – not speed as you might expect – isn’t just a saying.
In 2017, Patrick Dubuque of Baseball Prospectus investigated the phenomenon and found that it wasn’t the raw gait rate that was slow to come back in many cases, but rather the command in and around the zone.
“UCL repair shops saw a worse strike average than before after returning from an injury,” wrote Dubuque Mechanics, bringing their pitches closer to the center of the record in hopes of getting on with their raw materials rather than precision. “
That seems to be in line with Rosenthal’s experience, as you can see pretty easily in this fastball location map. (It’s also worth noting that having more pitches in the middle could avoid walks, but not hard contact as his hit rate was in the worst 41% of career.)
And so we come back to the original question: how much weight should you put on a shortened 2020? What does 23 2/3 innings mean after two seasons that were either completely injury-related (2018) or terribly bad (2019)? The answer is different for different players. There is never a right answer. In Rosenthal’s case, we would say that 2020’s performance means a lot. We’d seen him great in the past. The speed remains excellent. The ability to throw punches looks a lot better. There is a story of pitchers that take a minute after Tommy John’s operation.
There are no guarantees of pitching as there are none in life. But if Hendriks was gone and we were leading a team that needed a heavily armed late inning helper, we’d be pretty sure we’d have a lot of confidence in Rosenthal to take on that role. Imagine saying that six months ago?
