I had the opportunity to watch the Los Angeles Dodgers game on Saturday, which saw Chad Billingsley face off with Barry Zito. While I knew Billingsley was having a resurgence of sorts, his stellar outing versus the San Francisco Giants on this day sent me to the Fangraphs leader board where you can see him currently at 2.3 wins above replacement — hanging out with the likes of Cole Hamels, Cliff Lee, and Madison Bumgarner. Despite posting just six wins thus far, it turns out that Chad Billingsley is having a rather superb season, and I’m not too sure that many saw it coming after a disappointing 2011.

It seems like Billingsley is kind of perpetually overlooked as a quality starting pitcher. In the last five years, he’s amassed 16.4 WAR, just a hair behind James Shields, Ryan Dempster, and Matt Cain in roughly the same number of games started. And if he’s been underrated for a number of years, it was 2011 that took a good deal of remaining luster off his coat, and much of it was earned.

In 2011, Billingsley’s strikeout rate fell below 20% for the first time since his rookie season, his swinging strike rate was down to 7.6%, representing the bottom of a three year slide, and his BB/9 rate was over four. He was using virtually the same repertoire and demonstrated no significant change in velocity yet his results weren’t close to his 2010 season.

One of the central problems Billingsley had in 2011 was getting hit hard by left handed batters. Lefties hit .278/.382/.415 off Billingsley in 2011, and much of that was wrapped up in a miserable 13% walk rate. This season, he’s walking lefties at almost half the rate at 7.4% and their overall line against him thus far is .249/.307/407. What, if anything, has he changed?

He hasn’t totally overhauled his approach, but there are some distinct changes in his pitch selection against left handers this season. He’s going to his four seam fastball far more regularly and he’s almost abandoned his cutter:

With this modification in approach versus LHB, he’s also seeing more swings and misses. Most notably on his four seam fastball and curve since he’s using them as his primary two pitches against left handed batters. The change isn’t dramatic to be sure, but it’s certainly progress for Billingsley.

So he’s changed his repertoire to go with a more fastball-heavy approach to LHB and he’s producing better swing-and-miss results. But then there’s all those pesky right handed batters, against whom he’s actually struggling by his standards. This might have to with a renewed interest in keeping his walk rate down and pounding the strike zone. His walk rate is at the lowest of his career at 6.9%, and if you’re a “per 9” fan, it’s just 2.67 versus his career rate of almost 3.8 BB/9.

The impact of the following chart is somewhat lost in the scale, but when you compare this year to 2011, he is working himself into pitchers counts more frequently and falling behind far less (I left 2-1 out because the results were almost identical and the percentages were so high that it threw the whole thing out of whack):

Billingsley isn’t a world-beater, he’s not the ace the Dodgers might have thought they had when they took him with their first pick back in 2003. But he’s finding success with his renewed approach, and better yet, if you’re a Dodger fan, he’s now seemingly signed to a pretty club-friendly deal should his health remain steady. The Dodgers are committed to $35 million through 2014, plus a club option for $14 million in 2015 when he’ll still just be 30 years old. He’s almost a lock to be a 3.5 win pitcher in 2012, and if he can maintain a 3 WAR standard over the next couple of seasons, that’s a pretty nice (and economical) complement to Clayton Kershaw, who can’t become a free agent until 2015.

He more than rebounded from a disappointing 2011. Billingsley seemed to learn from the down year and he and the Dodgers consciously modified his approach without making wholesale changes to the kind of pitcher that he is, and that plan has been awfully successful in 2012.