J.A. Happ is boring. Even if he finishes the season with an ERA under 3.00 and 20 wins he’s not going to win the Cy Young because he’s the chapter you skim to get to the sex scene. His face looks like one of those composite pictures of a million Caucasian faces that’s supposed to show what the average white dude looks like. His shaved head is perfectly rounded on top like it was molded by a baseball cap. His delivery looks like some engineering student made a pitching robot for some tech fair. I guess that’s why they call it mechanics.

Happ’s blown away all expectations this season, but if you’re digging for that “one weird trick” he’s discovered, you’re about three years too late.

The fastball has always been Happ’s go-to pitch. During his awful 2013 campaign, he started tinkering with its release point, and in 2014 he dropped it pretty drastically. Here are some GIFs so you can see for yourself. The first is from 2012 and the second is from 2016.

Here’s a side by side screenshot of his release points to make it a bit clearer. Left is an over the top sinker from 2012. Right is a lowered sinker from 2016.

Looking at his fastball runs above average (per 100 pitches) we can see the lower arm slot juiced up the pitch. In 2012, hitters slugged .516 off his fastball and batted .293 on his sinker. In 2016 they are batting just .188 against the four seam and .247 off the sinker.

The reason that value of the pitch has skyrocketed is because it’s finally doing sinker things. Here’s what’s happened to Happ’s ground ball rate on sinkers since he made the change. His overall ground ball rate has also risen every year since 2013, which is great because fly balls are dangerous things to play around with at the Rogers Centre.

If there’s one thing you can point to that he’s changed this year it’s that he’s leaning more heavily on that sink fastball, which he now releases over half a foot lower than before. But let’s not fool ourselves into thinking this is a Matt Shoemaker level situation. Happ identified that his sinker was a useful pitch and is now using it more. He’s not going crazy with it. He might not even realize he’s doing it.

Look as hard as you want, but there just aren’t that many differences between 2014/2015 Happ and this year’s version. His K/9 and BB/9 have been more or less the same for the past three years. Ditto for the quality of contact mix he’s allowed – his Hard% has been between 31% and 33% over that span. His strike zone approach hasn’t changed either; he stays low and away to righties like his life depends on it and he throws strikes 45% of the time like clockwork. His velocity has fallen a tiny bit but it’s nothing serious.

So we’ve got a guy who make a small tweak and found a great sinker a few years back, and has fancied himself and ground ball pitcher ever since. But here’s the thing about being a ground ball pitcher: you need a good defence to make it work. This is the basic concept behind DIPs theory and FIP. Pitchers have no control over what happens after contact is made (well, maybe some do) so defence is crucial those in the ground ball game.

Besides Edwin Encarnacion, there’s not a single name from the Jays 2014 infield still standing today. Jose Reyes‘ weak arm, Brett Lawrie‘s error prone ways, the Juan Francisco experiment…smh. The year before was even worse, with Emilio Bonifacio manning second instead of Munenori Kawasaki. According to Def, the 2015 Pirates squad got the worst marks of any of Happ’s teams since he began generating more ground balls with his revamped sinker.

Then you have the 2016 Jays, lead Kevin Pillar‘s outstanding glove in center field and Troy Tulowitzki and Josh Donaldson on the left side of the infield. Mix in Devon Travis‘ solid work at second base and Russell Martin‘s legendary presence behind the plate, and you have a team that ranks in the 84th percentile by Def. It hasn’t just been Happ taking advantage of this incredible defence: rotation mates Marcus Stroman and Aaron Sanchez rank first and second in the league, respectively, in GB/FB ratio, and are both in the top-five GB%.

It’s a big change, but its not one that Happ himself made. You could view it as the final missing ingredient to his bland, bland recipe of dominance; as if he all he needed was an elite defence to unlock the full potential of his new sinker. I would argue that the breakout has been 25% Happ and 75% not Happ. A big part of that 25% is the simple fact that he’s having a great situational season.

That .176 batting average with men in scoring position is part BABIP luck and part defence and should regress towards his consistent ~.250 mark, but it does look like he’s figured something out. When Toronto signed Happ for $36 million this off season, most fans viewed it as a milequetoast Plan D after David Price left for Boston. It was totally milquetoast. There is no denying that. But if GM Ross Atkins identified Happ as a pitcher who might reach another level in front of Toronto’s defence, it was also a genius move.