We've heard a lot about Kameron Loe this season. He's tall. He used to own a snake. He went to Japan. For a while, he was a bullpen savior. But lately, after posting a 7.71 ERA in his last nine outings, he's become something of a bullpen scapegoat. The problem is, I'm not sure it's his fault.
A brief history
Loe was a 2002 draft pick for the Rangers, and climbed the ladder pretty quickly. He made his major league debut after just his second full minor league season (in 2004, his age 22 season). He appeared in 48 games for the Rangers in 2005, then was used primarily as a starter in 2006 and 2007, posting a 5.54 ERA in 48 appearances (43 starts).
After appearing in just 14 games in 2008, Loe left for Japan and spent a season there, but was relegated to the minors and used sparingly, appearing in just five games for the Fukuoka Hawks. He was signed by the Brewers this spring and sent to Nashville, where he worked as a starter and posted a 3.16 ERA in ten starts, and made his Brewers debut on June 1.
The change
Despite the fact that he had been a starter in the minors and for most of his career, the Brewers put Loe in the bullpen, and have used him a lot. Since his Brewer debut on June 1 Loe leads all Brewer relievers in appearances and relief innings:
| Pitcher | Games | IP |
| Kameron Loe | 34 | 38.1 |
| John Axford | 28 | 32.2 |
| Todd Coffey | 27 | 21.1 |
| Zach Braddock | 27 | 20 |
| David Riske | 23 | 23.1 |
| Trevor Hoffman | 23 | 22.2 |
In fact, after a brief search I was only able to find a few major leaguers who have pitched more often than Loe since June 1, and none of them have pitched as many relief innings:
| Pitcher | G since 6/1 | IP |
| Javier Lopez | 36 | 25 |
| Sean Marshall | 35 | 36.1 |
| Peter Moylan | 35 | 24.2 |
| Pedro Feliciano | 34 | 23.1 |
Historical Context
After allowing a home run to Troy Tulowitzki on Friday, Loe was given Saturday and Sunday off. Even considering that rest, he's pitched 34 times in 65 games since being called up to the majors. Ken Sanders holds the Brewer franchise record for most relief appearances in a season, making 83 in 1971. Loe's pace translates out to 84 appearances over 162 games.
Furthermore, if Loe played a 162 game season at this pace he'd pitch 95 innings, becoming just the second Brewer reliever to do that since 1989:
| Pitcher | Season | Games | IP |
| Ken Sanders | 1971 | 83 | 136.1 |
| Tom Murphy | 1974 | 70 | 123 |
| Chuck Crim | 1989 | 76 | 117.2 |
| Jim Slaton | 1983 | 46 | 112.1 |
| Chuck Crim | 1988 | 70 | 105 |
| Tom Tellman | 1983 | 44 | 99.2 |
| Bob Wickman | 1997 | 74 | 95.2 |
| Kameron Loe | 2010 (proj.) | 84 | 95 |
Entering this season, Loe had never made more than 40 relief appearances in a season, and his major league high for innings was 136. He's already made 34 relief appearances now (plus ten starts in AAA), and already pitched 98.1 innings this season.
Results
Obviously the sample size is small, but Loe has already made ten appearances on zero days' rest. Here's how they compare to the rest of his outings:
| Situation | G | IP | ERA | FIP |
| Zero days' rest | 10 | 8.2 | 4.15 | 3.78 |
| All other situations | 24 | 29.2 | 2.12 | 3.53 |
Conclusion
Over the course of his career, Kameron Loe has not demonstrated that he is an elite major league pitcher, so some regression to the mean should probably be expected. However, the Brewers are doing him no favors by using him at a record-setting pace despite the fact that he's still not very experienced at pitching out of the bullpen.
Certainly, all pitchers have different thresholds and abilities to bounce back, but it's hard to believe a pitcher like Loe could pitch as often and as long as he has without experiencing some fatigue-based issues. The fact that we have to go back 20 years or more to find Brewer pitchers to compare him to should tell you something about how difficult it is to pitch effectively this often.
As I just mentioned, Loe should probably expect some regression to the mean as his season goes along. But given his usage pattern, I think we also have to consider fatigue as a possible, and maybe the most likely, cause for his struggles.