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October 10, 2011 Resident Fantasy GeniusCan Pitchers Control Their Consistency?
In my preview of the NLDS between the Brewers and Diamondbacks last week, reader mopup1 posted a comment relating to something I’ve been meaning to look into for a while now. I'm sure Derek and anyone in a weekweek fantasy pool knows this but Gallardo's prone to S*it the bed at times. 6 times this season he's allowed 5 ER or more. His inconsistency is a big issue IMO in a playoff scenario. Fans and analysts often talk about how a particular pitcher is inconsistent or how another is prone to a dominating or disastrous outing, but I’ve never seen a study looking at whether this sort of consistency (or inconsistency) is a repeatable skill. Surely it happens—as mopup1 said, Gallardo took several beatings this year—but is it something that the pitcher has any control over, or is it merely random luck? You see, for forwardlooking purposes (like fantasy baseball), it only really matters if it’s something the pitcher can control. Otherwise, it’s nice to look back on and mention, but it wouldn’t tell us anything about whether the pitcher will be similarly consistent (or inconsistent) in the future. To study whether starttostart consistency is a repeatable skill for a pitcher, I’m going to look at several different measures of a pitcher’s performance in a given start:
ERA: Earned Run Average
The Study From here, I’m going to look at all pitchers who started at least 20 games in backtoback seasons since 2002 and compare their consistency (as measured by standard deviation) between the two years. To do so, I’m going to run a correlation, which measures the relationship between two sets of numbers. The closer to zero, the weaker the relationship; the closer to one, the stronger the relationship. The Results
While a pitcher’s consistency in terms of my own True Quality Starts holds the strongest yeartoyear relationship, it’s still a very weak relationship overall (since 0.07 is much closer to zero than it is to one). What this tells us is that, no matter how we want to measure a pitcher’s success on a startbystart basis, a pitcher’s consistency from starttostart is largely unpredictable. Even if he was extremely consistent one year, he could just as easily be inconsistent the next year.
Application to Fantasy Leagues Pitcher A who allows 8, 0, 8, 0, 8, and 0 runs or Pitcher B who allows 4, 4, 4, 4, 4, and 4 runs? While both average the same number of runs allowed and Pitcher B is more consistent, Pitcher A is going to win more games because he’s almost assured of a win in his 0run starts (Pitcher A would win something like 2.3 games to Pitcher B’s 1.1 games). Of course, this is a moot point since the study shows inconsistency to be largely random. *It’s interesting to note that, while consistency is often the trait people value in a pitcher, an inconsistent pitcher is actually going to provide more value. Who is going to win more games,4 comments have been left for this article.

Honestly, the point reached by this article is useful (to some degree). But I have two problems with this:
1) Clicking on the link to TQS takes us to a nonBP article explaining the process. I understand that Derek created the metric before writing for BP. However, the fact that BP hasn't incorporated said metric (despite all the factors that it accounts for) is a bit of an issue. Anyone who writes a BP article where they include a bunch of stats, including their own nonBP verified metric, and then magically has their own data come out first....it's a problem for me.
2) Let's say that nothing in comment #1 is a problem, and that statistical research completely and thoroughly verifies every point that Derek makes. Even if that's the case, I'm disappointed by this article. What sold me on Baseball Prospectus was the quality of the writing that accompanied the statistical analysis. Rany Jazayerli, Nate Silver, Joe Sheehan, Christina Kahrl  this is what brought me here. These people (along with current BPer Jay Jaffe and others) knew how to combine the narrative of an event with statistical analysis, and I rarely left their articles without the information I needed to evaluate their claims. Derek's point is interesting, potentially valid, and worth considering. However, it's shallow, poorly written, has a grand total of ONE supporting data set, and it's flatout uninteresting in its current format. The final of these points is the most damning for me. BP might be a lot of things, but it should never be boring.