Wily Peralta’s Win Total and Irrational Exuberance


Jul 8, 2014; Milwaukee, WI, USA; Milwaukee Brewers catcher Jonathan Lucroy (20) talks with pitcher Wily Peralta (38) during the second inning against the Philadelphia Phillies at Miller Park. Mandatory Credit: Jeff Hanisch-USA TODAY Sports

Despite Tuesday’s loss, Wily Peralta is still tied for the Major League lead with 14 wins. The other pitchers with 14 wins are Clayton Kershaw, Adam Wainwright and Johnny Cueto, all aces.

Due to his win total, many Brewer fans have developed the irrationally exuberant opinion that Peralta is also an ace, and if he isn’t now, he probably will be in the future.

So today, I want to dive into Wily Peralta and see what is really going on with his performance this season.

We’ll start with some basic numbers to look at his win total. Peralta is currently sporting a 3.46 ERA, good for 20th in the National League. However, the Brewers are scoring 4.46 runs per game in support of Wily, the 9th highest run support in the National League.

Those two numbers tell part of the picture already. Peralta is giving up just under 3 1/2 runs per nine innings, and the Brewers are scoring just under 4 1/2 runs in his starts.

We can also look at no-decisions. Wily only has three no-decisions on the mound this year:

  • April 5th: He left with a 6-5 lead, the Red Sox tied it against Jim Henderson, and the Brewers won in extra innings.
  • May 14th: He left in a 1-1 tie; K-Rod gave up three runs in the ninth to lose.
  • July 2nd: He left in a 4-4 tie, Will Smith and Brandon Kintzler gave up three runs in the ninth to lose.

Aug 7, 2014; Milwaukee, WI, USA; Milwaukee Brewers pitcher Wily Peralta (38) plays with the ball between pitches in the sixth inning during the game against the San Francisco Giants at Miller Park. Mandatory Credit: Benny Sieu-USA TODAY Sports

That  explains Wily Peralta’s win total in my mind. It is a combination of run support, and the fact that the bullpen has only blown one lead given to them by Peralta this season.

So Wily Peralta’s win total is mostly based on positive run distribution and luck. The Brewers offense gives him piles of runs, and the bullpen hasn’t cost him any wins.

But with all the fans calling him an Ace, just how good is he really?

We already looked at his ERA, good for 20th in the league, but we can do better than that. We’ll start with a few ERA estimators.

In terms if FIP (Fielding Independent Pitching), Peralta is 37th in the National League out of 46 qualifying starting pitchers. Fun fact, despite his positive performances in the bullpen, Marco Estrada is still dead last in the league.

So, FIP doesn’t like Wily Peralta. What about SIERA (Skill-Interactive ERA)? Wily’s SEIRA is 3.73, good for 22nd out of 46 qualifying starters.

FIP doesn’t like that Wily strikes out so few batters (just 6.62 per nine innings), but SIERA gives him credit for having a team-best (and fifth in the NL) 54.6% ground ball rate. That many ground-ball outs can lead to some unlucky hits, but they lead to more outs, and double plays than you’d see out of a fly ball pitcher like Estrada.

Now we’ll look at another non-mainstream reference: Game Score.  Game score isn’t quite as fancy as the ERA estimators above. It is really a replacement for the Quality Start, which is a pretty poor metric given that a pitcher with a 4.50 ERA could earn a quality start every game.

The average Game Score in the National League this year is 51. Wily Peralta’s game score this year is 53.0.

Jonathan Judge over at Disciples of Uecker recently used Game Score to evaluate if the Brewers offense actually does perform poorly against bad pitching (hint: it doesn’t), and had a nice break down of pitchers with Game Score.

Wily’s 53 Game Score puts him squarely in the Jonathan’s “Average-Plus” category. It is a level below aces like Wainwright, Kershaw and Felix Hernandez, but it is a good place to be.

What is interesting is that this is exactly what the scouting report was on Wily when he came to the major leagues. When he harnesses his ability and stops with the mental lapses (that became so common for him in 2013), he would become a solid middle-of-the-rotation starter. In 2014 we stopped seeing Peralta shout at himself on the mound in the middle of tough innings, and he’s cut his walk rate by a full walk per nine innings.

So that is exactly what Wily Peralta has become. He is a solid middle of the rotation starter who won’t give you too many stinkers a season but will probably never be a Cy Young candidate either.

So, how do you think Wily’s career will play out. Let us know in the poll and in the comments.