Examining the Tribe bullpen with BER
It doesn’t take too much number crunching to realize how good Red Sox reliever Koji Uehara has been this season. Just scan his pitching line. It’s all right there in front of you. What this postseason has done, though, is help the country realize just how historically great the righty has been this year.
Examining Uehara’s numbers got me thinking again about a stat I’ve been contemplating for a couple seasons. I’m calling it Bullpen Efficiency Rate. Basically, a reliever’s job is to get in and get out as quickly and efficiently as possible. I wanted a number that summed that up and wasn’t hard to calculate.
Here’s what I eventually settled on: (Outs + ROE) / (Batters Faced – IBB)
The goal here is to determine the percentage of time a reliever is efficient in creating the desired result. I added Reached On Error to Outs, because — generally speaking — a pitcher did his job in an ROE situation, whether that’s inducing a ground ball or creating a fly ball that is then misplayed by the fielder. For the second part, I subtracted Intentional Walks from Batters Faced, because that stat is extremely situational, and often called by the manager and out of the pitcher’s control.
After poring through both good and bad seasons by a wide range of relievers, here is the scale I came up with for the results:
86-90% = Unhuman
81-85% = Elite
76-80% = Great
71-75% = Good
66-70% = Poor
61-65% = Send Help
Here are the 2013 numbers for the Indians’ most-used relievers:
1. Joe Smith 74.7
2. Bryan Shaw 73.9
3. Marc Rzepczynski 73.8 (STL/CLE)
4. Matt Albers 73.6
5. Cody Allen 71.9
6. Nick Hagadone 71.2
7. Chris Perez 68.0
8. Vinnie Pestano 67.1
9. Rich Hill 65.9
That is why, in an earlier post, I went with Smith over Allen as my pick for the Tribe’s best reliever for 2013, even though their other numbers were very similar across the board. Shaw is a great example of how including ROE and IBB can alter the stat. Without ROE and IBB, his BER would be 71.2 percent. Shaw was a little snakebit, though, with seven ROE this past season. Take that and IBB into account and his BER spikes by 2.7 percent.
For comparison, Uehara posted a BER of 85.2 in 2013, giving him one of the greatest relief seasons in baseball history. The closest I could find — in a search of single relief seasons from 1950-2013 (min. 50 innings) , sorted by highest FIP – was Dennis Eckersley, who posted an 85.1 BER in his incredible 1990 season. The best FIP since 1950 belongs to Craig Kimbrel in 2012, when he had an 82.3 BER. Behind Kimbrel on that list are Eric Gagne (2003; 81.6 BER), Eckersley (1990) and Greg Holland (2013; 80.3 BER).
Mariano Rivera had an 83.0 BER in 2008, which was arguably the best season of his Hall-of-Fame-caliber career. And the long-time Yankees closer had a 77.1 BER during his time in the big leagues.
On the other side of the equation, John Pacella posted the worst FIP in the sample I pulled from 1950-2013, back in 1982. His BER that year was 63.3. Another rough season was Mike DeJean in 1999, when he had a 66.4 BER. For Indians fans who want to forget all about the Brett Myers Experiment, his BER in 2013 for the Tribe was 67.0. As well as Hill did with inherited runners, his 65.9 BER shows how much trouble he got into throughout this past season. In theory, a lefty specialist should have a high BER, because he only faces a hitter or two before being pulled. Randy Choate (76.6 BER in 2013) comes to mind.
How did Cleveland compare as a team to other American League bullpens?
Here are the 2013 BER team rankings:
1. KC 75.5
2. TEX 73.9
3. MIN 73.8
4. TOR 73.5
5. BAL 73.4
6. TB 73.3
7. OAK 72.7
LEAGUE AVERAGE 72.3
8. NYY 72.1
9. BOS 71.8
10. CLE 71.7
11. CWS 71.5
12. DET 71.4
13. LAA 71.3
14. SEA 70.2
15. HOU 68.9
You’ll find that the league WHIP rankings come close to how BER shakes out for the American League. You could also run BER for a starting pitcher, or for a team’s pitching staff as a whole, but my goal here was to limit it to relievers. I wanted something to throw lefty specialists, closers, middle men, long men and other bullpen arms together with one stat to show the efficiency of their work. For a starting pitching, given the high volume of innings, the BER scale would likely include slightly lower percentages to gauge success. For example, Clayton Kershaw was at 79.4 percent this past season.
What does this mean for the Indians’ bullpen for 2014? It could mean that the back end will be fine in the hands of guys like Allen, Shaw and Rzepczynski, if Smith and Albers leave via free agency. It also shows how re-signing Smith and/or Albers has the potential to help stabilize things, and that improving the lefty relief options should be a priority. If Cleveland is in the market for a new closer (Perez isn’t a lock to return, or regain that role), it’s easy to run the candidates’ BER to see if it’s the kind of efficiency needed in the ninth inning.
Feel free to provide feedback. No stat is without its flaws.
UPDATE: A few readers have pointed out that this stat is essentially 1 minus on-base percentage against. That’s true and I’m not claiming to have reinvented the wheel here. It is a slight variation of that concept, and is simply a different way to look at it. Taking ROE and IBB into account changes the result by a small margin, but enough to arguably be deemed significant, especially in certain cases (such as the Shaw example given above).