Doug Fister is an ace. He is. There’s no getting around it. It wasn’t supposed to be like this, but here we are. Twenty two months after the Mariners sent him to the Tigers for a package of players that are either no longer in their organization or are Charlie Furbush and Chance Ruffin, Doug Fister has established himself as one of baseball’s best starting pitchers.

This year, he currently ranks 9th in WAR with 2.8 and 5 of the guys above him on the list have made at least one more start than he has. He takes the mound tonight and could reasonably push himself into the top five range. It’s not just this year, it’s been every year. Last year he missed a quarter of the season with an oblique injury and still ranked 27th in WAR. Only Medlen and Strasburg out-pitched him in fewer innings.

Since the start of 2011, only five starting pitchers have a higher WAR. Justin Verlander, Clayton Kershaw, Cliff Lee, Felix, Hernandez, and CC Sabathia. That’s it. That’s the whole list. Fister missed a quarter of the season in 2012 and since the beginning of 2011 only five pitchers have been better and they all have at least 70 more innings in that span.

Don’t get me wrong, the number of innings you pitch matters a great deal, but it’s important to note. Doug Fister, despite missing time, is holding his own with the best handful of starters in MLB. How is he doing it?

Fister doesn’t throw hard. His fastball averages 88-89 mph. He does it with command, movement, and pitch selection and he does that better than anyone else. Jered Weaver is the only other starting pitcher in the top 25 in WAR over the last 3 seasons to average a fastball under 90 mph and Weaver is 9 spots behind him on the list.

It is Fister’s excellent command and brilliant offspeed pitches that make him so good and he’s getting better.

The ERA takes a hit in 2012 and 2013 thanks to his defense, but the FIP and xFIP are trending down and it’s thanks to a real change in his approach.

Fister is striking out more batters and walking even fewer than his already impressive baseline. And even more than that, he’s turned himself into an elite groundballer. Only 3 qualifying starters have induced more groundballs than Fister in 2013:

I mean, just look at that. Look at it! Fister is getting pretty much the same number of line drives as always but he’s cut his flyball rate nearly in half and turned them all into groundballs. This isn’t always great for his BABIP, but it’s great for his overall run prevention. Balls on the ground can’t turn into homeruns and they don’t turn into extra base hits. Fister is striking out more batters, walking fewer, and getting everyone else to hit the ball on the ground more often. You couldn’t design a better transformation than this one.

I talked about the same type of transformation recently with Porcello, and he and Fister are in rare company. They have strikeout rates above 7 per 9, walk rates below 2 per 9, and GB% above 50% in 2013. Since GB% started being recorded in the early 2000s, the only starters to finish a year like that are Halladay, Carpenter, and Hamels. Felix, Porcello, and Fister are trying for it this year.

Essentially, what we’re looking at with Fister is another member of the Detroit School of Pitching. I looked at the team trends here, and how it’s working for Porcello (above), Sanchez, and Scherzer so far. Jeff Jones or whoever is calling the shots, has helped the Tigers starters master the changeup and optimize their breaking ball mix. Here’s how Fister has developed his approach:

The top graph separates the breaking balls and the bottom one combines them. He’s gone from slider (some people call it a cutter) to curveball and increased the use of his changeup over his fastball. This is something almost every Tigers pitcher is doing, and it’s really working for Fister.

He’s inducing less contact and based on the batted ball data it is weaker contact:

He’s 5th in BB% and he’s 10th in FIP and he’s doing it while allowing the third lowest HR/9 in baseball this year. He’s become an extreme groundball pitcher who strikes out a decent number of batters while walking almost none. In fact, he’s nearly hit as many batters as he has walked, which is exceedingly rare.

Take a look at how his curveball is moving more and his changeup is separting more from the fastball, but my goodness look at the shift in movement in his fastball.

Doug Fister’s numbers point to him being one of the game’s best starters this year and over the last few seasons. He’s racking up the WAR and is striking guys out, not walking many, limiting homeruns, and adding groudballs. He’s preventing runs and doing just about everything you could ever want a starting pitcher to do and he’s doing it all with a fastball under 90 mph and has never recorded a pitch of 95 mph or higher.

Which means he doesn’t grab headlines. And if you’ve ever heard an interview with him, you know he has no interest in headlines. It’s always about his team. Which makes him endearing. And likable, and my god, he works extremely quickly on the mound. And he shatters bats, which I love.

The Mariners gave him to the Tigers for a reasonable package at the time, but since the trade those guys haven’t panned out and Doug Fister as gone from a nice back end starter to a bona fide ace. He’s my favorite starting pitcher to watch in baseball. His fastball breaks more than most people’s breaking balls and his pinpoint control and snappy pace are so refreshing. Not to mention his cat-like reflexes and great defense.

He’s basically the perfect starting pitcher. It’s about time someone noticed.