Now the Rick Porcello skeptic is going to look at his 5.92 ERA and just ignore this post in favor of his or her preconceptions about the Tigers right-hander, but I urge you to read on. Rick Porcello is about to have his breakout season. Really.

First, let’s point out that his start on April 20th against the Angels was a mess. 0.2 innings and 9 runs. But it certainly wasn’t all his fault, it was only somewhat his fault. There were infield singles galore in that inning and he should have gotten out of it with  only a run or two to his name. I don’t mean to deflect the blame, but merely want to to point out that type of strange inning can happen to anyone and that he induced 7 groundballs in 2/3 of an inning. Normally, that should get you a lot of outs. If we remove that start from his line this year, he has a 3.85 ERA. Again, I’m not trying to just wish it away – it happened – but I do want to point out that other than that one inning, he’s having a very solid season for back end starter even by a conventional, inch deep approach to analyzing baseball.

But let’s also turn to the peripheral numbers. Rick Porcello is striking out 6.39 batters per 9 so far in 2013 and that is the highest number of his career. In his first two years he was about 4.7 K/9. In 2011-2012 he was 5.0-5.5 K/9. He’s added nearly an entire strikeout per 9 this season, which is always a good thing.

He’s also walking fewer batters than ever. In his first season he walked 2.74 per 9 and in his last three he’s been around 2.1-2.3 BB/9. This year, he’s walking 1.89 batters per 9 inning. Look at how his strikeout rate and walk rate are bowing apart on the graph. That is a sign of improvement.

He’s striking out more hitters and walking fewer. In other words, he’s getting better at two of the aspects of the game a pitcher can truly control. But there’s more.

Rick Porcello’s groundball rate is rising too. In his rookie season he got 54.2% GB, but that number dropped to 50.3% before rising each of the last three seasons into this year’s career high 54.9% groundball rate. Not bad. More groundballs are always better than more flyballs.

And then there are the homeruns. Typically Porcello has allowed 0.8 to 1.0 HR/9, but this year that number is 1.42. Now that may sound worse, but it’s actually good. The reason being that most people consider HR to Flyball rate to be inherently driven by luck and that over a large enough sample, every pitcher regresses toward giving up about 1 HR per every 10 fly balls. Porcello has generally been in that range for his entire career. Until this season. This season that rate is 1 in 5. Again, this is a good thing because we would expect that number to come down toward his career norm, thus shrinking his HR rate as the season goes on. In other words, Porcello has given up more runs that he should have this year because he’s been unlucky with flyballs and that luck will change.

Put this together and we have this story: Rick Porcello is striking out more batters than ever, walking fewer batters than ever, getting more groundballs than ever, and is allowing more homeruns per flyball than we would generally expect. All of this points toward the 24 year old having his best season to date.

I’m buying it. Everything we know about what makes pitchers successful tells us to look at strikeouts, walks, and homeruns and the percentage of balls in play he allows on the ground versus in the air. All of those numbers – all of them – are trending in the right direction for Rick Porcello. Lots of people talked about his great spring and the trashed it when he struggled a bit early, but here were are on May 18th and Porcello is starting to make himself look like a very good starter.

Fangraphs furnishes a metric called xFIP which gives us an expected ERA for a starting pitcher based on his strikeouts and walks plus a regressed version of their HR rate adjusted for park effects and league average. Rick Porcello is posting a career best 3.42 xFIP right now. That xFIP is 27th best in baseball among pitchers with 30 IP or more. He’s tied with Jordan Zimmermann (who has a 1.69 ERA) and is getting ace-like attention this season.

I’m not trying to make the case that Porcello is a #1 starter or even a #2, but rather that Rick Porcello is poised for a breakout season and that you should take notice. Heck, look at how his xFIP has declined in every season of his career. He’s often a whipping boy for fairweather fans and idiot radio hosts, but Rick Porcello has always been a durable starter and now he’s having his best season yet.

And he’s still just 24.