Top Five Pitching Duos

When the Dodgers signed Zack Greinke this offseason, he gave them — along with lefty Clayton Kershaw — one of the top front-ends of a rotation in baseball. Together, the duo may have one of the best one-two punches in the game, a duo truly capable of winning four games in a seven-game series. Are they the best in the game? Let’s take a look.

First, a couple of parameters. I selected the top two of each rotation based on the player’s projected WAR totals, courtesy of Dan Szymborski’s ZiPS system, which has just finished running over at FanGraphs. I also took the combined WAR of each duo for the past three seasons. I use three seasons, because any one season can be subject to small sample size or statistical flukes, so when possible — as it is here — three years makes for a better sample. However, WAR isn’t the end-all be-all, so we want a couple of other metrics as well. A pitcher’s peripheral statistics, such as strikeouts and walks, often hold a great deal of predictive value, but rather than dividing them by each other, as K/BB does, it’s better to subtract the two percentages from each other. This not only gives it more predictive value (which you can read more about here) but it also makes more sense intuitively, as you are using the same sample in your denominator – total batters faced. Finally, we want to have a projected rate stat to account for the fact that not all pitchers are projected to have the same workload (for instance, ZiPS projects Gio Gonzalez to toss 200 innings this year, but projects Clayton Kershaw to toss 221.2, a large difference), so we’ll use the ZiPS projected ERA for each duo. By using all four of these metrics, we can get a more complete picture of how the duos have performed, and how they may be expected to perform. In doing so, five duos emerged.

5. Jered Weaver, C.J. Wilson – Los Angeles Angels of Anaheim

Weaver and Wilson have been very productive over the past three years, and likely will be again this season. Both rank in the top 10 in WAR over the past three seasons, placing them in the top five as a duo. But where they fail to reach the top is in their strikeout and walk ability. Collectively, their strikeout and walk rates are middling, though the walk rate can be laid at the feet of Wilson much more so than Weaver. Though Weaver doesn’t walk many, he does a poor job of keeping the ball on the ground, but thanks to his ballpark and outfield defense, this isn’t the issue for him that it would be on a different team.

4. Gio Gonzalez, Stephen Strasburg – Washington Nationals

Strasburg is at once the reason to be wary and optimistic for the Nationals. There isn’t a starter in baseball who has a better FIP- projection than Strasburg’s 58 FIP- heading into this season. But Strasburg also has the thinnest track record, thanks to his Tommy John surgery. As a result, he has a fairly thin track record — just 251.1 innings pitched in the majors, and not one season with 30 starts. On the other side is Gonzalez, who made a lot of strides last season but still walked batters at a rate above that of league average. The two may top this chart a year from now, but at the moment it is prudent to exercise a little caution.

3. Justin Verlander, Max Scherzer – Detroit Tigers

Last season was Scherzer’s coming out party, as the young righty — who was part of the famed three-way trade that also involved Curtis Granderson, Austin Jackson and Ian Kennedy — saw his strikeout rate skyrocket. Instead of making contact on more than 78 percent of the pitches they swung at, opposing hitters were only able to connect on 74 percent of Scherzer’s pitches in 2012, a number that was good for fourth in the game among qualified starters. As for Verlander, he essentially duplicated his Cy Young Award-winning season, though the instinct of writers who wanted to want to craft a different narrative led them to select David Price for the honor instead. Still, few are going to do it better than Verlander, who ZiPS projects to have the most WAR among starting pitchers this season.

2. Cliff Lee, Cole Hamels – Philadelphia Phillies

You could make the argument that Halladay deserves to be placed here rather than Hamels, but coming off a down year, Hamels has a higher projected WAR than does Halladay. And certainly Hamels is no slouch, as among the number-two starters as defined by this exercise, only Mat Latos has a higher projected WAR for 2013. Lee and Hamels form the most efficient pairing. Both few waste bullets, particularly Lee, whose 3.9 % walk rate is easily the game’s lowest over the past three years. Over those past three years, they have been the most valuable duo, and there is little reason to expect much of a drop-off this season. Lee received attention for his drop in wins last season, but if there’s any reason for worry among Phillies fans, it’s that both his K rate and swinging strike percentage fell last season. But he also was able to limit his walks more, which dampened most of the negative effect.

1. Clayton Kershaw, Zack Greinke – Los Angeles Dodgers

Indeed the Dodgers’ new duo is the last team on the list. No pair of pitchers that a team can put together can match the 10.4 WAR that ZiPS projects Kershaw and Greinke to achieve this season. The Nats might come close if Strasburg were pegged for more innings pitched, but it remains to be seen if the nanny state Washington placed him in will lead to the 200-inning season they expect from him. Like the Phillies, Los Angeles has a pair of very efficient pitchers. It’s become de rigeur to doubt Greinke, but he has been worth at least four wins in each of the past five seasons, giving him an exemplary track record. It’s that track record that makes him more bankable than Scherzer or Strasburg, who have just a single season of domination under their belts. And while Kershaw didn’t match his brilliant 2011 season in the same fashion that Verlander did, he joins Verlander as one of two pitchers to notch a WAR projection north of six wins.

We can probably eliminate the Angels from the discussion, as well as teams like the Giants, Yankees and Rays from the best one-two punch discussion, but Washington, Detroit, Philly and the Dodgers are all so talented that picking one team as definitively the best is akin to splitting hairs. Having said that, the Dodgers may have the best balance of past track record and future projection, and that puts them in position to tip the scales in their favor. LA may not have the best overall rotation, but with Kershaw and Greinke, they are going to be tough to beat.