I’ve been looking forward to Friday for a long time: the O’s come to Atlanta for the first time since Leo Mazzone took his magic bag to Baltimore. I’d planned to go to at least one game, but it looks like I won’t make it. Since I published my study on Leo’s effectiveness last year at The Baseball Analysts, I was curious to see how he and Braves pitchers would do away from each other. The interesting development of Russ Ortiz making his first start under Mazzone against the Braves on Saturday is going to put Mazzone in the spotlight even more.
It’s very hard to get a sense of what has really happened since Mazzone left. For one, there’s the sample size issue. There are so many factors involved in ERA differences across teams, and ERA is a statistic that varies widely; this requires a larger sample than half-a-season. Second, the two teams play in different leagues with very different pitchers. Straight comparisons of ERAs would tell us very little even if we had an adequate sample.
One way to look at this is to compare the pitchers Leo coached last year on the Braves to their performances this year. I looked at this in this post, and found that those pitchers were doing considerably worse this year. Although, I didn’t look at the Orioles.
Another way to look at the issue is compare how the overall staffs of the O’s and Braves are doing this year versus last year. While both teams have experienced some turnover, there are many constants on both teams. So, here is a second way to look at the teams. The table shows the differences in ERAs between this season and last season, with a few corrections.
BAL ATL Difference 2006 (Raw) 5.18 4.67 0.51 2006 (RC) 4.96 4.37 0.59 2006 (LC) 4.76 4.37 0.39 2005 (Raw) 4.57 3.99 0.58 2005 (LC) 4.37 3.99 3.38 Difference 0.37 0.38 -0.01
The first row is the raw ERA of both teams in 2006. The second subtracts the difference in runs between this year and last year, as both leagues are yielding more earned runs than last year. The third row corrects for the differences in ERA between leagues, by subtracting the average difference in ERAs between leagues from the Orioles (I could have added it to the Braves). The fourth row lists the 2005 ERAs of both clubs, and the fifth corrects for the difference between leagues. The last row reports the difference between the roughly-corrected 2006 ERAs to the 2005 (LC) ERAs.
As everybody knows, both clubs’ pitching staffs have not done well this year, and their fortunes have been quite similar. What does this show? I have no idea, probably not much at all. It’s likely that both clubs are struggling to adapt to new pitching coaches.
It’s also interesting to look at the ERAs over time. As of late the O’s and Braves have been moving in opposite directions.
Month O's Braves April 5.54 4.56 May 5.54 4.48 June 4.43 4.98
The O’s have done much better in June, but is this a random fluctuation or a sign of things to come? It’s interesting to note that back in April, Orioles manager Sam Perlozzo suggested June as the time Mazzone’s influence would show.
All along Orioles Manager Sam Perlozzo has tried to temper people’s expectations about Mazzone. He wouldn’t work miracles right away, warned Perlozzo, who believes that by June people will see tangible evidence of why Mazzone is considered the best pitching coach in baseball.
“I don’t think that’s unreasonable,” Perlozzo said. “Right now with many of the guys being away at the [World Baseball] Classic they’re learning on the job right now. You have certain habits you’re used to. And it takes practice. I think you’ll see [Mazzone's effect] later on.”
Obviously, it’s too early to tell what is going on, but I watch with great anticipation.
Addendum: I’m going to link to stories discussing Mazzone’s return here. If you see others, I’d appreciate it if you would please pass them along.