Trevor Rosenthal, out of Lee’s Summit, Missouri, was the St. Louis Cardinals’ 21st round pick in the 2009 MLB draft. What an incredible value Rosenthal has become for St. Louis just four years after the draft. One day, he will most likely become the closer for the Cardinals, but right now, he is making the most out of his set-up man role.
Rosenthal throws straight heat. We all knew this, but how does he compare to other pitchers throughout the league? The average speed of a Rosenthal fastball this season is 96.3 MPH–good enough for fourth among pitchers who have thrown at least 20 innings. Aroldis Chapman is the highest with an average speed of 97.4 MPH–just 1.1 MPH faster than Rosenthal.
Since Chapman is widely considered the gold standard of late-inning relief pitchers, I will further compare Rosenthal to Chapman for the rest of this post. Not including the obvious difference between Rosenthal being a righty and Chapman being a lefty, they really are not that much different.
Rosenthal has topped out at 101.4 MPH this season while Chapman has touched 101.8 MPH. Thus, when needed, Rosenthal is able to reach just about the same top speed as the flashy Chapman. Comparing the end result of their fastballs gives the advantage to Rosenthal who has a better batting average against–.191 to Chapman’s .211.
The one big advantage that Chapman has over Rosenthal is his breaking pitch. Chapman loves his slider and for good reason. At this point in the season, the batting average against on his slider is a remarkable .000! He has thrown it 82 times this season. Rosenthal has thrown only 63 off-speed pitches all season–which includes his curveball/slider and changeup.
Thus, advantage goes to Chapman in this category, but Rosenthal’s incredible control in spotting his heater has given him great success so far in his young career. As he develops, with players like Adam Wainwright and Chris Carpenter around to mentor him, he will be able to fine-tune his off-speed pitches and gain confidence to use them in high stress situations. He does have good off-speed pitches, it is just hard to compete with Chapman’s incredible slider. (PS, you REALLY want to check out that video).
Rosenthal has pitched 32 innings this season with a 1.69 ERA while recording 46 strikeouts to just 6 walks. Chapman has pitched 28 innings with a 2.25 ERA. He has 48 strikeouts and 12 walks. Thus, Chapman might rack up more strikeouts, but as shown in Sunday night’s game on ESPN and by the statistics, Rosenthal is more efficient and has better control–something that allows Matheny to extend him beyond just one inning if needed.
Rosenthal, drafted by the Cardinals, is still in his pre-arbitration years and is making $490,000 this season. Chapman, who signed with the Reds out of Cuba, is making ten times that much at $4.9 million in 2013. Special thanks goes out to Cardinals scout, Aaron Looper, for the enthusiasm he showed about Rosenthal (who was a SS/P at the time) that convinced the front office to draft him. Because of Looper’s work, the Cardinals are not only blessed to have arguably the best set-up man in baseball right now, but they also have the luxury of employing him at such a great value (as shown above).
Thus, I do not at all disagree with all the hype that Chapman has received since he signed with the Reds from Cuba, but I also think that Rosenthal deserves just as much hype based on his stuff and his performance. Both are great young pitchers with tremendous upside, and as a Cardinal fan, I am thankful that at least one of them is on my team for years to come.
Until next time…
Special thanks to PITCH f/x for the raw data used in my comparison between Rosenthal and Chapman