Wainwright-Greinke duel one to watch

In 2009 and 2010, Adam Wainwright was as good as just about any pitcher in baseball. He ranked third in adjusted ERA behind only Felix Hernandez and Roy Halladay. Only five guys threw more innings and only CC Sabathia won more games. Wainwright finished third and then second in the National League Cy Young voting.

He hurt his elbow in spring training last year and missed the entire season after undergoing Tommy John surgery. His start Saturday against Zack Greinke is one of the more intriguing matchups of baseball's first weekend. Given Chris Carpenter's health issues, a successful return by Wainwright is even more imperative for the Cardinals.

Wainwright's signature pitch was his knee-buckling 12-to-6 curveball that he threw nearly 29 percent of the time in 2010. The only starters who threw a higher percentage of curveballs than Wainwright that year were Wandy Rodriguez and Gio Gonzalez. Two things made Wainwright's curve tough to attack: (1) He set it up with good velocity and location on his fastball, throwing 91-92 mph; (2) great location on the curve. Check the heat maps below: Wainwright spotted his curve low and away to left-handed hitters ... and low and away to right-handed hitters.

So while everybody's eyes will likely be on the radar gun, it may be Wainwright's command of his curve that tells us how he'll do as he returns. No matter what happens Saturday, it's an anticipated game for the Cardinals and their fans. "It really is a big deal," Cardinals general manager John Mozeliak told MLB.com. "I'm probably going to have a few butterflies before that game even starts, just knowing how hard he's worked to get to where he is."

Meanwhile, Greinke gets the ball for the Brewers on the heels of Yovani Gallardo's four-homer Opening Day stink bomb. If you want a Cy Young candidate in the National League not named Halladay, Kershaw or Lee, Greinke may be your guy. Greinke finished 16-6 with a 3.83 ERA in 28 starts in 2011, and while that 3.83 ERA might not impress you, it comes with a big caveat: an extremely unlucky average on balls in play in the first half of the season.

Greinke's BABIP in the first half was .349, which led to a 5.45 ERA even though he had 99 strikeouts and just 16 walks in 74.1 innings. In the second half, his BABIP returned to a more normal level of .304 and he posted a 2.59 ERA.

Here's a heat map of Greinke's pitch locations in the first and second halves of 2011. While this doesn't tell the whole story of setting up hitters and so on, you can see the hot points are pretty similar. It does suggest that Greinke was merely unlucky in the first half, with a few too many bloopers, flares and infield hits.

What does it mean? If Greinke pitches like he did in 2011, when he led the NL in strikeouts per nine innings at 10.5, he's more likely to come closer to that 2.59 ERA than 3.83. Greinke also loved pitching at home last season -- he went 11-0 in 15 starts while averaging 11.3 K's per nine. The one aspect Greinke needs to improve on to become a legit Cy Young contender -- and remember, he won the American League award in 2009 with the Royals -- is to pitch deeper into games. He pitched more than seven innings only twice last season.

After Gallardo's disaster, there's nothing the Brewers would like more than eight innings from Greinke and the chance to hand the ball to John Axford with the lead.

Follow David Schoenfield on Twitter @dschoenfield.