Stats & Info: Brian Fuentes

Bullpen sorrows start on South Side

April, 16, 2011
Thorn in Chicago’s Side
The White Sox finished 14 games over .500 last season thanks in part to a strong bullpen. Chicago relievers combined for a 3.73 ERA in 2010, which ranked fifth in the AL. The squad also blew only 14 saves, third fewest in the American League. But manager Ozzie Guillen’s all-too-public rant this week on the state of his bullpen has made it clear that this year has already gone very differently. Through 12 team games Chicago’s save percentage is a scant 14.3, worst in baseball. The six blown saves are already nearly half of the team’s total last year.

Which man is the biggest culprit? Closer Matt Thornton, who has four blown saves in as many opportunities. Thornton’s strength in 2010 has become his weakness in 2011, and that is eliminating batters with two strikes against them. Last year, the lefty converted 79 percent of two-strike at-bats into outs, six percent above the average player according to Inside Edge. So far in 2011 that number is hovering around 53 percent.

Of the seven hits Thornton has allowed in two-strike counts this season, six have come off of his fastball. It’s not certain who is the closer moving forward, but Sergio Santos is a likely candidate.

Other Staff Shining in Philly
Jose Contreras
The offseason was full of talk over the Phillies dominant starting staff. While that aspect is starting to come around this season, the bullpen has quietly posted the lowest ERA in baseball (1.93). Hitters have amassed just a .214 batting average and a miniscule .541 OPS, second lowest in MLB this season. The Philadelphia bullpen has kept at-bats economical as well (averaging 3.83 pitches per plate appearance which ranks among the top 10 in baseball). Jose Contreras has performed admirably as interim closer for Brad Lidge; he’s yet to allow a run in three appearances while collecting two saves.

He's Back
Brian Wilson has made a nice return this season. In a four-day span between April 12-15, Wilson earned three saves in as many appearances. He allowed no runs or walks, just a single hit and struck out four in those games. Wilson also utilized his fastball nearly 60 percent of the time and did not allow a hit off of that pitch. His velocity is a bit down, as in that stretch his fastball averaged 94.3 miles per hour (fastball averaged 95.7 miles per hour last season), but it hasn't seemed to hurt him.

The case against ERA & introducing RPA

March, 31, 2010
Picture this: Top of the 9th inning, two out, men on second and third and the home team is up three. With the setup man unable to finish the game, the manager calls on the closer who he was trying to rest. The crowd goes wild as the bullpen doors open, but the noise quickly turns to silence as the closer gives up a two-run double. With the lead down to one run, the crowd rallies to the aid of the closer who induces a harmless ground ball. Game over.

Final stat line for the closer: (Save) 1/3 IP, 0 R, 0 ER, H, 0 BB, 0 K.

ERA: 0.00

Situations similar to this occur somewhat frequently in baseball. For years pitchers have been judged on ERA, wins, losses, saves and strikeouts. While this formula may work for starters, it leaves a lot to be desired for relievers. Relievers can’t be evaluated by ERA. ERA is based on 9 innings and most relievers rarely pitch more than an inning or two per game. Runs, and even more importantly, inherited runs scored are far more important in measuring a reliever’s success.

Now, you may be wondering how unearned runs can be counted against a reliever. It doesn’t seem fair does it? Well, the reality is relievers have one job to do: Come into the game, and get out of jams. Whether a reliever comes in with the bases loaded or no one on base, his job remains the same. That job, again, is to come into the game and leave the game with the score the same way as when they entered.

So, with this in mind I set out to create a stat that took into account the two most important stats for a reliever: runs allowed, and inherited runs scored. Rather than divide this number by innings, I chose to divide by appearances.

The result is the following formula that I dubbed “Runs Per Appearance” (RPA): Runs allowed plus inherited runs scored divided by pitching appearances.

The results are simple, like the formula. Good pitchers had solid RPA averages while pitchers who were helped by errors and inherited runs scoring and not their own, were exposed. Check out the results below.

Here's another way to illustrate it. While both Jamey Wright (4.33 ERA last season) and Manny Acosta (4.34 ERA) had similar ERAs, their RPAs (1.123 and .639 respectively) differed greatly. The league average among all relievers last season was .935. That takes into account all long relievers, closers, setup men, and specialists. So Wright had a below-average performance in terms of RPA while Acosta actually had an above-average season in terms of RPA. His .639 RPA is far from Mariano Rivera or Joe Nathan status, but it was most certainly above average for a reliever.

Is (R)uns (P)er (A)ppearance (RPA) a perfect stat? Absolutely not. However, RPA does tell a much more accurate story for relievers than ERA. If nothing else, this should be something interesting to track in 2010.