What’s the reason for Jason Vargas’ early dominance?

There was a day last week when Royals starter Jason Vargas was the best pitcher in baseball.

Though that’s not something I ever expected to be typing, a screenshot from Fangraphs WAR leaderboard Thursday gives the proof.

So how is this happening? How has a 34-year-old with a max fastball of 89 mph this year turned himself into the game’s most dominant starter over the first three weeks?

The answer, mostly, appears to be the improvement one pitch — and Vargas altering his mechanics since Tommy John surgery in 2015 to help make it one of the best in baseball.

Brooks Baseball provides the clearest view of Vargas’ shift. This graph shows his vertical release point in each of his major-league seasons.

Not only is Vargas pitching from a lower arm slot, but the data also shows he is releasing his pitches roughly 2 inches more toward first base this season compared to last year while using more of a slinging style. While this feels like something minor — we’re talking about a matter of inches here — it seems like this adjustment has helped bring out the absolute best in his change-up.

According to Pitchf/x data, Vargas’ change-up has a 3-inch shift this season in horizontal movement, breaking further toward his arm side.

It’s all led to this ridiculous chart from Baseball Savant.

From 84 change-ups this season, Vargas has gotten 26(!) swinging strikes, while allowing three hits, which all have been singles. As a whole, the league is hitting .103 with a .103 slugging percentage against that pitch, a line that equates to being 137 percent worse than league average.

According to Pitchf/x’s weighted run values, Vargas’ change-up is not only the best in baseball, but as of last Thursday, it also was the third-best pitch of any in the majors, behind only James Paxton’s two-seam fastball and Ervin Santana’s curve.

So what’s the difference? Here’s a look at synched-up video of the two pitches from 2016 and 2017, which again shows the pitch slightly tailing away more this year from right-handers’ bats.

It’s too soon to know if this change-up dominance will keep up. Vargas likely didn’t become Chris Sale overnight, though an unexpected boost like that could go a long way towards helping the Royals stay in contention.

The only surety, at this point, is that Vargas’ arsenal has changed, with most of that centering around a pitch that has been nearly unhittable.

And though Vargas’ change-up might not continue to be the best in baseball, it certainly has earned that title so far.

This story was originally published April 24, 2017 at 11:44 AM with the headline "What’s the reason for Jason Vargas’ early dominance?."