When Blue Jays GM Alex Anthopoulos acquired SP Marco Estrada from the Brewers this past offseason for 1B Adam Lind, the logic behind the move was fairly easy to see. The Jays needed arms, and they had an extra bat to use as currency. They made the deal and both sides have enjoyed success from their respective players. Lind is on pace to up just over 2 WAR for a team that is going nowhere while not paying him a ton, and Estrada is having an unexpectedly great year for a team having it's best season in 2 decades.
But is he really having a great year? I can hear you out there saying "of course! 11 wins and an ERA just over 3? That's fantastic!" And that's a fair point of view to have unless you understand the failings of those two stats in particular. ERA gives credit to the pitcher for everything that happens on the playing field after the ball leaves his hand, including good and bad defense, hit sequencing and random luck. Wins give credit to the pitcher for giving up 8 runs, while your offense scores 10. It's just not good. There are better ways to judge a pitcher's skillset and value.
So back to Marco Estrada and his ERA just over 3 with 11 wins. The book on Estrada prior to this season was a typical one for a lot of pitchers. He doesn't throw hard, he relies on command and control and gives up too many home runs. And boy, did he love to give up home runs! With a tip of the cap to Fangraphs for providing the numbers, you can see that somehow Marco Estrada is getting good results, despite having some of the worst numbers of his career. Estrada Fangraphs
In comparing Marco Estrada in 2015 to his past years, we will focus on 2012-2014, since those are the years he threw the most comparable amount of innings to what he will throw in 2015. From 2012 to 2015, Estrada has seen his strikeouts go from 9.3 K/9 to just 6.98 K/9 this season. His walk rate has gone up each year from 1.89 BB/9 in 2012 to 2.89 BB/9 in 2015. But how does that make sense if Estrada is seeing his best career ERA while his K numbers drop and his BB numbers rise? There are two main reasons for this, and the first is home runs.
Estrada has been adept at avoiding the long ball in Toronto despite historically serving up dingers at either near or above league average every other year he has pitched. His HR/FB% has gone up each year from 2012 at 10.5%(MLB average was 11.3%) to 13.2% in 2015(MLB average 10.5%), yet in 2015 he has managed to give up only 7.6% of HR on his fly balls(MLB average is 11.1%). That's a pretty big decrease over last season, especially considering Rogers Centre is a notoriously homer friendly park and Estrada continues to be a fly ball pitcher in 2015(51.1% - also the highest of his career). A career high in fly ball rate plus the friendly confines of his home park alone should give us pause and expect that more balls are going to be leaving the yard in the future.
The second part of Estrada's wizardry in 2015 is due to a massive decrease in his BABIP(batting average on balls in play). MLB average BABIP in 2015 is .295. It doesn't change much from year to year as it was .295 in 2014, .294 in 2013, .293 in 2012 .. etc. Suffice to say BABIP is typically very stable, whether you're the best pitcher in the game or one of the worst. Marco Estrada has a .229 BABIP, good for the lowest mark amongst all SP with the arbitrarily chosen 120 innings pitched or more. The effect of a low BABIP is not hard to see; fewer people getting hits, even with an increase to walk rate, means there are fewer men on base, which means fewer runs scored even if he does give up a home run, which we've seen already that he's avoiding this year despite having his career worst fly ball rate.
This is not meant to say that Estrada is a bad pitcher. In fact, you can see why Anthopoulos was interested in him as a trade target as a guy who was quite likely getting unlucky in the amount of homers he gave up, while still striking out his share of batters and walking relatively few. This year however, the strikeouts are down, walks are up yet, and his home run rate and BABIP are well below what history tells us we should be expecting from him. Every year there are pitchers around baseball who benefit from awful defense, bad sequencing, bad luck and others, like Estrada, who benefit from great defense behind them, beneficial sequencing and luck. That's baseball. But when that guy shows up on a TV broadcast being compared to Chris Sale and Felix Hernandez (looking at you Rogers Sportsnet.... REALLY!?!?), when a closer look at his supporting numbers quite clearly indicates that regression should be expected, we should thank our lucky stars that Estrada has the results he has for the Jays and just hope that it continues until the end of the season and playoffs. When the regression comes, it will probably be very ugly.
Interesting. Career ERA a third of a run less than his xFIP is probably partially a result of this (as well as defense that DRS thinks is plus).