The thing that had held Rick Porcello back during his first four major league seasons was his inability to generate strikeouts. He limited walks, induced plenty of weak ground balls, and never got hurt, but he couldn't put batters away when he got ahead. In 2013, his strikeout rate shot up to 19.3% after four seasons in the 12-13% range. Porcello started striking hitters out and it turned him into an above average MLB starter. The breakout happened last year, but the leap into stardom is happening right now.
In 2013, Porcello junked his slider for a curve and started making better use of his changeup to the tune of more swinging strikes and more strikeouts. He posted career best numbers in Fielding Independent Pitching (FIP) and Expected Fielding Independent Pitching (xFIP) at 3.53 and 3.19, which are two statistics that you read like ERA but do their best to strip defense from the equation.
And stripping defense from the equation was important for the 2010-2013 version of Porcello. He's a ground ball pitcher who was tossing ground balls in front of a horrible infield defense, especially in 2013. His ERA was 4.32 last year (partly due to a pair of blowup starts against the Angels), which might not seem like anything special, but every underlying number screamed breakout. More strikeouts, limited walks, lots of ground balls. He wasn't simply a number five starter anymore, he was a bona fide above average major league pitcher.
At 24 years old that was plenty impressive. Justin Verlander didn't become Justin Verlander until he was 26. Max Scherzer didn't become Max Scherzer until he was 27. Just because Matt Harvey and Jose Fernandez dominated from day one doesn't mean we should expect young pitchers to be at their best right away. Porcello is younger than Stephen Strasburg, if you can believe it.
As Porcello enters his prime (he turned 25 this offseason), the last of his flaws are vanishing. I've always been one of Porcello's biggest believers, but even I couldn't put him among the game's best pitchers before 2014. This year, he's barreling his way into the conversation.
His strikeout rate isn't quite what it was last year, but it's better than 2009-2012 and he's essentially stopped allowing walks (3.5 BB% in 2014) and home runs (0.68 HR/9). Now that he has better defense behind him, he's not allowing nearly as many hits. He's running a career low BABIP at .266 and a career low batting average against at .236 to go along with his 2.91 ERA and 3.21 FIP.
There are two very important improvements to Porcello's game that have turned him from a good pitcher with a bad defense to a pitcher who would easily be a number two starter on more than twenty teams.
First, Porcello figured out left-handed batters. From 2009 to 2013, Porcello allowed lefties to tag him for a .304/.358/.461 line (.357 wOBA). In 2014, that line is .235/.272/.361 (.278 wOBA) against the first 103 lefties he's faced. He's always been very tough against right-handed hitters, but Avila has guided him much better against southpaws this year to the tune of significantly weaker contact.
Porcello's other remaining flaw was his difficulty with men on base. From 2009 to 2013, Porcello allowed a .298/.365/.454 line (.357 wOBA) with men on base. In 2014, he's allowing a .241/.267/.375 line (.276 wOBA) with men on. It's amazing how similar those two improvements have been. He's cut about 75 points of wOBA against lefties and with men on base.
As Porcello matured in late 2012 and during most of 2013, he was still susceptible to the big inning. Not anymore. He stopped issuing walks with men on base and stopped allowing hard contact with men on and to lefties. Mix that in with Porcello's already impressive profile against righties and with the bases open and there really aren't any significant holes in his game.
He's learned to make better use of his breaking ball and changeup in conjunction with his always impressive sinker over the last year and it's turned him into a star. Not a good number five, not an above average pitcher, but a star.
Most people consider the best fifteen or so starters to be the league's "aces." Porcello ranks 16th in FanGraphs WAR over the last calendar year. He's 15th in park adjusted FIP. He's 11th in park adjusted xFIP. He's 22nd in RA9-WAR (which is based only on runs allowed, park effects, and innings pitched). If you don't want to classify him as an ace, I can live with that. He's right on the fringes. But if he's not an ace, he's in that next class of starters.
It's so easy to forget that Porcello is only 25 because he's been around forever and it's easy to think he's pedestrian because he's the fourth best starter on one of the best rotation in MLB history. But if you look at Porcello on his own, he isn't just good enough, he's great. It's time to appreciate his growth and probably time for Dave Dombrowski and the Tigers to make sure he doesn't make it to free agency after the 2015 season. Last year was the Porcello breakout, but this is the Rick Porcello leap.