Twins Pitchers by ERA+


Sometime ago, Wally noted that Joe Nathan has the best ERA+ out of all relievers since 2004.  Naturally, I got to wondering how he stacks up among the franchise pitching leaders, so I made a little chart.  

I took every pitcher who has ever pitched for the Twins in franchise history, then sorted them by ERA+. These are the top 20:

As you can see, Nathan is far and away the best pitcher by ERA+ in franchise history. Of course, ERA+ has its problems. It tends to be skewed in favor of relievers because they tend to have much higher ERAs in terms of innings pitched. When we look at the top 20 franchise leaders in wins above replacement (which tends to favor starters because of innings pitched), things look a little different:

That isn’t to say that Nathan hasn’t been a very good pitcher over the years, he’s been one of the best relievers in baseball since 2004. It’s just that in context, a very good reliever isn’t worth nearly as much as an above-average starter. After all, Nathan missed all of the 2010 season, and yet the Twins still managed to clinch their sixth division title in eight years, thanks in large part to the contributions of Francisco Liriano and Carl Pavano (well, and Joe Mauer, Jim Thome, and Orlando Hudson, but this post is about pitchers). Of course, the bullpen is much thinner this year than it was last season, and there is little doubt that a healthy Nathan will provide a much-needed boost. However, a healthy Nathan isn’t going to make-or-break the season, either; that will depend a lot more on the health of Scott Baker, Kevin Slowey, and Carl Pavano.