A.J. Burnett's Pittsburgh renaissance

The Pittsburgh Pirates' success this year has been analyzed from a variety of angles, and one of the more fascinating aspects of it -- at least for geeks like me -- is an enhanced use of infield shifts based on spray-chart data.

Of course, this kind of progressive thinking is often met with resistance from players, and not everyone loves this philosophy. In fact, A.J. Burnett was recently quoted in the Pittsburgh Tribune-Review as saying, "I have a problem with (expletive) shifts."

There's a decent bit of irony here because no pitcher has benefited more from the Bucs' use of shifts than Burnett, who has been reborn in Pittsburgh over the past two seasons, and pitched one of the best games of his career on Friday night, shutting down the Reds over eight innings in a 4-1 victory. With the win, the Pirates are now one win away from hosting Tuesday's National League wild-card game.

Burnett needed just 99 pitches to get through eight innings, striking out six and walking just one. Perhaps more impressive were the 11 ground-ball outs he induced, as compared to just two fly outs. As discussed within this Travis Sawchik piece, the Pirates have put an extra emphasis on the two-seam fastball, which is designed to induce ground balls. In Burnett's two seasons in Pittsburgh, his ground-ball rate has been above 56 percent after never cracking 50 percent in his time with the Yankees.

All those ground balls play perfectly into the arms of the Pirates' shift, and this was evident with two outs in the sixth inning when Jay Bruce -- a dead-pull hitter -- ripped a ground ball toward right field. In a traditional alignment, that's a clean single. But with second baseman Neil Walker playing in short right field, with shortstop Clint Barmes just a few feet to his right, it was an easy out.

However Burnett might actually feel about shifts, there is no doubt that he has adjusted his pitching approach with the Pirates, and he has thrived as a result. Per FanGraphs, he's accumulated almost 7 wins above replacement in two years with the Pirates after barely cracking 2 WAR in his last two seasons with the Yankees.

Burnett has talked about retiring after this season, which means that this could be his last major league start. Part of me hopes that Burnett keeps pitching in Pittsburgh to see if he can continue this late-career renaissance. I get the sense that history won't be that kind to Burnett because his results have never seemed to match his stuff, particularly earlier in his career when he would alternate dominating starts with duds, while collecting big-money deals from the Blue Jays and Yankees. There was always a bit of a Nuke LaLoosh element at play with him, it seemed.

But here's the thing: He's had a pretty good career. I tend to think pitcher wins are fairly useless in single-season samples -- Burnett is 10-11 this year despite a 3.30 ERA -- but they are a decent quick-and-dirty method for measuring career value. Burnett now has 147 career wins with an ERA of 4.00, which is above average for the hitter-friendly era in which he spent most of his career. For context, his career ERA+ is 105, and that's identical to Jack Morris' ERA+, and he has eight more wins than Johan Santana.

Whatever Burnett's legacy ends up being, he'll certainly be remembered fondly in Pittsburgh, especially after tonight.