On Monday night, the Brewers defeated the Padres 4-3 at Miller Park. The win was their 15th on the year, against only 5 losses, and their 4th victory in a row. Perhaps the most under-appreciated hero of the team’s early hot start is starter Wily Peralta. The Crew have won all 4 of Peralta’s starts thus far this season, three of the four which qualify as “quality starts.” So just how good is Peralta? The answer to that question goes a long way towards explaining how sustainable this run might be. Let’s look at some factors driving his improvement early this year:
1) Fastball, Fastball, Fastball
Peralta has always been primarily a fastball pitcher, but according to Fangraphs he’s throwing them even more this year than last, 69.9% of the time which is up from 66.7% in 2013. Brooks Baseball actually breaks that number down further, into 4-seam and sinkers, and he’s currently relying more than ever on his heaving sinking fastball. At least this season, that pitch is generating about 3 times the number of swings and misses as his straighter 4-seamer, though that isn’t a clear trend that extends back to last season.
When Peralta isn’t throwing one of his two fastballs, he’s almost exclusively throwing his sharp slider (26.9% of the time total) instead of the changeup (3.1%) which he’s never seemed to fully trust, and even less so early in 2014. It should also be noted that Peralta’s average fastball velocity of 95.2 is currently 6th among all qualified starters in MLB according to Fangraphs, and having that kind of velocity gives pitchers wiggle room to miss and not get punished for it quite as often as someone sitting 89-91 might.
2) All of the Ground Balls
Wily Peralta has always been a ground ball pitcher, even going back to his minor league days coming up through the system, but it’s a trend that’s become even more pronounced in the early going in 2014. Thus far, Perlata is generating a ground ball 56.9% of the time when batters put the ball in play on him, a number that’s up from 51.0% last year. Perhaps even more importantly, Peralta is currently allowing fewer line drives (15.3%) than last year (21.3%). Line drives are the type of batted ball most likely to result in a safe hit, so limiting this number is a good way to prevent runs.
Peralta is also generating more infield popups than last year, a full 20% of his fly balls have stayed within reach of the infielders, as opposed to 8.2% last season. While that number hardly seems sustainable over the long haul of the season, neither does 20.0% of his fly balls ending up as home runs. Last year, Peralta only saw 11.9% of his fly balls to leave the yard, which was about 1 percent up from the league average of 10.5%. So even when we see some expected rise in his line drive rate and drop in ground balls generated, chances are he won’t be allowing home runs as often as he has early on this season.
3) Why Unearned Runs Exist
It’s fashionable (and rightly so) these days for people to scoff at the idea of “unearned runs” and to thus dismiss the idea of Earned Run Average, or ERA. After all, the difference between and earned and an unearned run really comes down to an often arbitrary decision by the official scorer. It’s fair to say that Peralta’s sparkling 2.19 ERA is somewhat misleading, because so far this year only six of the eleven runs to score on his watch have been “earned.” If we were to just dismiss the idea of earned runs, his runs allowed average would be a much-less-impressive 4.01. How fair would this be, though?
Peralta truly has been on the receiving end of some pretty bad defense, and not just the 3 errors that have been made behind him thus far in 2014. The standard (for want of a better term) SABR-line on things like this is “well, if you don’t want unearned runs to score, don’t put men around the errors and you’ll be mostly OK.” The problem with applying that logic to Peralta this year is he actually is doing a pretty outstanding job of keeping runners off the bases this year. His WHIP (walks + hits / innings pitched) is 1.09, well below the major league average of 1.30 and down from an unsightly 1.41 in 2013. So it’s really not like Peralta has put a lot of runners on base and deserves all this extra punishment from defensive misplays to his runs allowed numbers.
4) Avoiding Walks
How has Peralta pulled off this improvement in allowing baserunners? We’ve already covered part of it when talking about his low line drive rate, which has his batting average against down to .219 this year after sitting at .259 last season. That’s a really big deal, but perhaps even more impressive has been his drop in walk percentage this year. In 2013, Peralta walked 9.1% of the batters he faced, well above the 7.4% league average. This year, he’s cut that down to 5.8%, or almost 2 points better than the league average of 7.6%. This is an outstanding development.
He’s pulled this off by throwing more pitches in the strike zone, 44.7% compared with 41.9% last year. He’s also seen a solid increase in the number of strikeouts he’s generated, up to 18.5% of batters faced from 16.1% last year. The overall result has been a major improvement in his K:BB ratio, from 1.77 in 2013 to 3.17 in 2014. That is going to help any pitcher have success.
The $64,000 question here is just how sustainable is this improvement? If Peralta can avoid a major slip in the number of line drives he’s allowing and consolidate his gains in terms of stikeout to walk ratio, we’re probably looking at a major breakout season for Peralta. I could throw numbers at you all day (and I have) but ultimately we’re still dealing with a very complex and very human set of variables here, so we’ll just have to wait and see how it all plays out.
ESPN.com’s Keith Law picked Peralta as one of his breakout candidates coming into 2014, and it’s not hard to see why. He has the kind of fastball velocity you just can’t teach and a body built to soak up innings at the big league level. It’s hard not to at least like the potential for a big breakout here, but only time will tell if it’s really happening or not.