On Tuesday I linked a piece that Tommy Bennett of Baseball Prospectus wrote about the best relievers in baseball. In this piece, Bennett discusses the difficulty involved when trying to evaluate Mariano Rivera, who consistently outperforms even the most advanced metrics. Rivera’s skill, Bennett concludes, is his apparent ability to sustain a low BABIP and to prevent home runs. Bennett’s underlying approach was interesting though. He gave each reliever a “score,” is based on their respective WXRL and SIERA scores. Here is how he describes his methodology:
We’ll take WXRL and SIERA for all pitchers who have pitched solely in relief. For each pitcher, we’ll calculate how many standard deviations they are away from the mean in each category. Then we’ll add them together. For example, a pitcher who was one standard deviation better than the mean in both SIERA and WXRL would get a score of two.
So I’ve followed his lead. Currently there are 11 teams with a reasonable shot at making the playoffs. In the American League they are the Yankees, Rays, Red Sox, Twins and Rangers. In the National League they are the Braves, Phillies, Reds, Cardinals, Padres and Giants. I examined each team’s bullpen and tried to pick the six relievers that were the best and/or the most likely to see action in the playoffs. I went with six relievers instead of seven for two reasons. For one, not every team has a set-in-stone seventh reliever. More to the point though, this exercise is about identifying the best relievers in the playoffs. The seventh man out of the pen in October is usually a clean-up guy who sees action only in low leverage spots. Picking the top 6 is a bit of inexact science, since it involves trying to figure out usage patterns for teams that I don’t watch regularly, but I did my best. As such, the following relievers missed the cut: Wakefield, Fisher, Aceves, Martinez, Feldman, Sonnanstine, Herndon, Webb and Hawkesworth.
The results are after the jump.
First, here are the top 10 relievers on contending teams. This chart contains their respective WXRL and SIERA data, as well as their Total Reliever Score.
As you can see, the Padres have a formidable pen. Their closer ranks second amongst all relievers, and Adams, Gregerson and Thatcher are all in the top 10. The Rays have two in the top 10 as well with Soriano and Benoit. It’s no surprise to see any of the other names on this list either. Teams that have no relievers in the top ten are the Twins, Rangers, Phillies, Reds and Cardinals.
Now I’ve taken the data and sorted by team, summing the Reliever Score for each team. This is a bit of a crude metric, and it would be interesting to see the weighted WXRL and SIERA data for all six relievers per team. Nevertheless, the higher the Reliever Score, the better. I’ll go from lowest to highest, so the first team is the worst by this metric, and the last team is the best. In last:
The Red Sox are held down by a very low score from Hideki Okajima. It’s possible that Okajima could be left off the playoff roster since they have a viable LHP option in Doubront. Michael Bowden could also make the roster. Their best reliever is Bard, and it’s not even close.
The Twins are second from the bottom. The only reliever with a positive Reliever Score on this list is Jesse Crain, who has outstanding results for the past two months: 27 IP, 4R, 1ER, 11 BB and 26 Ks. The losses of Joe Nathan and Jose Mijares have been tough for Minnesota, even though they added Capps. Capps’ early results have not been good and Mahay has struggled this year. This leaves them with Glen Perkins as their only other left-handed option. Frankly, the Yankees match up very well with the Twins.
The Yankees are currently third from the bottom. This is the result of a very low score from Damaso Marte. Simply removing him would vault them near the top. There is considerable upside in the Yankee bullpen. David Robertson continues to pitch very well and is getting more and more high leverage work. Additionally, this score doesn’t include contributions from Kerry Wood. The two wild cards going forward are Marte, who pitched well in the playoffs last year despite taking most of the year off, and Alfredo Aceves, who is making his way back from injury. Both are on track to return in September, changing the makeup of the bullpen significantly.
Ryan Franklin continues to perform adequately in the closer role, and McLellan joins him with a decent year. The Cardinals just lost Jason Motte to injury, so his lack of contribution may weak them going forward. Frankly, it’s hard to predict how LaRussa will manage his bullpen in the playoffs, but it doesn’t appear to be a very strong group.
The Phillies are an interesting case. Their best reliever is Ryan Madson, who continues to be spectacular in 2010 and should post a higher WXRL as he accumulates more innings this year. Lidge has a positive Reliever Score, but most Phillies fans remain frightened when he tries to close out the game. His repertoire is very predictable; using Lidge over Madson in high leverage spots could come back to hurt the Phillies in October.
The Reds have a solid if unspectacular bullpen. The thing that makes them dangerous, though, is that their best relievers have been their middle relief guys. This means that they will be pitching in high leverage spots not in the ninth inning, which maximizes their value and results in greater probability of success. Shh, don’t tell Dusty Baker.
The Giants have the reliever with the highest Reliever Score amongst contending teams in Brian Wilson. This is no mirage: Wilson has a 12.5 K/9 this season with a 3.4 BB/9 to go along with his 2.05 ERA. Whatever he’s doing is working. Sergio Romo is no slouch either, with a 9.4 K/9 rate and a walk rate better than Wilson: 2.0 BB/9.
Neftali Feliz continues to shine for Texas while Darren Oliver provides a very good option from the left side. Frank Francisco gets a lot of heat for his epic meltdowns, but his peripherals remain strong (10.3 K/9, 3.0 BB/9) and this metric puts him in a moderately favorable light as well. The description of Francisco sounds a lot like what’s going on with Joba Chamberlain, and Francisco has a higher Reliever Score than Chamberlain. Another name to watch is Alexi Ogando, who has an infintisemal ERA and a solid strikeout rate. He’s been dominant in his last 10 outings, and has reportedly added a changeup to his repetoire.
According to these metrics, Benoit has been the Rays best reliever so far in 2010. Combined with Soriano, the Rays have a formidable end of game tandem. There’s considerable flux in the back end of the bullpen, with Balfour on the DL and Sonnanstine shifting back and forth from the rotation to the bullpen.
Surprisingly, the Braves clock in with the second-best bullpen among contending teams. Billy Wagner has continued his Hall of Fame-worthy ways, and Takashi Saito and Jonny Venters have pitched very well for Bobby Cox. Martinez looks good in early work but it remains to be seen whether he can sustain these results. He’s been a reliever with excellent control in his entire minor league career but doesn’t possess elite strikeout ability.
In first place are the San Diego Padres. Bell, Adams and Gregerson are the best trio by this metric, and provide great options for the Padres in the playoffs should their young starting staff falter. It could get very late very early for a team that finds itself getting outscored by the Padres in the playoffs.