Felix Doubront Is Going to Be Really Good

When Felix Doubront won the Boston Red Sox fourth starter’s role out of Spring Training, there were plenty of reasons to believe that the 24 year old Venezuelan could be an above average back-end of the rotation guy. 73 1/3 innings into first full season, Doubront has been a revelation. His 9.94 K/9 rate ranks fifth in all of baseball, trailing names like Stephan Strasburg and Gio Gonzalez and just ahead of names like Zach Greinke and Justin Verlander. With a BB/9 rate (3.44) that is a reasonable distance from league average, Doubront is more likely to be an ace than a back of the rotation guy.

Thinking about Doubront’s potential is enough to make a Red Sox fan forget about the team’s woeful record and where they rank in the division for a moment. It doesn’t hurt that he is pitching in the same division as the most hyped pitching prospect in baseball this year, Tampa Bay’s Matt Moore. Entering the season, Moore was a the concensus number one pitching prospect in baseball and the Ray’s were so confident in his abilities that they signed him to a five year, $14M deal before the season even began. With a 9.40 K/9 rate, Moore has not disappointed, but he has not been quite as good as Doubront thus far.

Moore is more than a year younger, though, and therefore he isn’t the best comp for Doubront. So, I decided first to look at all 24 year old rookie starters to see where Doubront might rank. The results are pretty exciting.

Here are the top 10 24 year-old rookie seasons since 1980 by fWAR

Felix Doubront is currently on pace to pitch around 180 innings, which would give him a shot at the top spot by fWAR. Only Brandon Beachy has a better strike out rate than Doubront among those here. Doubront’s FIP (3.84) would rank just eighth among this group, but with a 14.3% HR/FB rate, the Red Sox lefty can probably expect better luck on the long ball going forward. His xFIP (3.44) would put him fifth in the rankings.

However, a quick look at the K/9 and BB/9 really highlights just how good Doubront has been thus far. At this point, only Beachy can boast a better strikeout and a better walk rate and Brandon Webb’s 4.8 fWAR season came with a lower strike out rate and a very comparable walk rate. Doubront is currently on track to put up one of the best seasons for a 24 year old rookie in the past 30 years and it will not take much more than a few lucky breaks to elevate it to the best such season.

There are some great pitchers on the list above, but if that is not enough to inspire you to dream on Felix Doubront, maybe you should look at this list of all the pitchers since 1980 who have had strike out rates over 9 K/9 in their age 24 seasons (rookie or not).

Pedro Martinez, Tim Lincecum, Kerry Wood… those are some dreamy names. While Doubront isn’t going to be anywhere near Lincecum’s 7.5 fWAR and he probably won’t quite reach Pedro’s 5.2 fWAR, he does fit right in with this group. Considering that just two lefties (Scott Kazmir and Johan Santana) make this list, Doubront is in some elite company.

Given those two very different comparable lefties, Doubront falls somewhere in between. His walk rate is almost exactly in the middle of the two. His strike out rate is better than both, but it may not stay that way over the 150-180 full season sample. He is closer to Kazmir in ground ball rate, as Santana has been one of the more pronounced fly ball pitchers in the game. At the age of 24 both pitchers had far more major league experience than the Red Sox new star. Kazmir had thrown 570 2/3 innings by the start of his age 24 season and that likely contributed to his early decline. Johan was splitting time in the bullpen and in the rotation from 2000-2003 and 2003, but he still had pitched 239 innings prior to his age 24 season. With far less experience than both, Doubront is striking out more batters and maintaining a very reasonable walk rate.

There is no way of knowing whether or not Doubront will sustain this level of performance up through 150 innings or more, and, unlike Matt Moore, his minor league track record never suggested this kind of dominance. However, with 318 batter’s faced, this sample is past the point (150 TBF) where strike out rates tend to stabilize and rapidly approaching the point where K/BB rates stabilize (500 TBF), so regression is unlikely to be extreme in the areas where Doubront stands out the most. Since he is still a young pitcher learning the game, it is also quite possible that he is actually improves. Regardless, Felix Doubront is a very, very good young pitcher and he is probably going to be a force on the mound for some time.