When the A's purchased Jesse Chavez's contract from the Toronto Blue Jays last year, the collective reaction amongst A's fans was "Really? Him?" The volume on the grumbling got turned up when we kept Chavez and got rid of key 2012 perfor...
When the A's purchased Jesse Chavez's contract from the Toronto Blue Jays last year, the collective reaction amongst A's fans was "Really? Him?" The volume on the grumbling got turned up when we kept Chavez and got rid of key 2012 performer Travis Blackley, and for good reason. Here's a list of Jesse Chavez's major league seasons by ERA coming into this year:
Those numbers are more terrifying than three Jack Custs playing outfield. It seemed to us that there was no reason for Jesse Chavez to be pitching for any major league team, much less one who had a division to win. In case anyone forgot, we did win it, despite the fact that Jesse Chavez pitched in games 143, 146, 147, and 156, giving up runs in 3 out of the 4 appearances, all A's losses.
The legend of Jesse Chavez had grown (shrunk?) to the point that this season, whenever Bob Melvin would even have Chavez warm up, we would immediately assume that BoMel was punting the game. When Chavez came into the game in the 13th inning against the Yankees, we all knew it was only a matter of time until the Yankees exploded for 4 runs and we would all go home unhappy.
Of course, we all know now what happened next. He promptly went 5.2 innings, giving up only 1 hit, 2 walks, and striking out 7. We were all surprised, but the gutsy performance lowered Chavez's season ERA to 1.83. While he did take the loss in his next outing against the Rangers, it seems, so far, that Jesse "Forfeit the Game" Chavez is a thing of the past. What changed, besides the fact that the A's front office team is a much better evaluator of talent than we are?
There are a few different aspects of his seemingly miraculous turnaround, but one of the main aspects is this: he wasn't nearly as bad as his numbers looked.
If you really want to vomit, go back and look at the Jesse Chavez ERA chart above, but I don't recommend it. The numbers seem to speak for themselves: he consistently, over multiple seasons, posted an awful ERA. But there are a few problems with those numbers.
First of all, sample size. In that 2008 season, when he posted a 6.60 ERA, he only pitched 15 innings total, and gave up a BABIP of .380. His xFIP for that stint was 4.20. In the 2011 season, when he posted an ERA of 10.57, he only threw 7.2 innings, and had a completely unsustainable 42.9% HR/FB rate. The league average is about 10%. In such a small sample size, his numbers never had a chance to balance out.That still doesn't help his awful numbers in 2010 and 2012, though. One cool statistic provided by FanGraphs is LOB% (left on base%). Research has shown that pitchers have almost no control over stranding runners- over time, most pitchers will have a LOB% around 70%. The idea of "bearing down" with runners on base has not been shown statistically. In the short term, though, a pitcher might strand a larger or smaller number of runners, inflating or deflating their ERA before regression takes hold. For relief pitchers, who pitch a much smaller number of innings than starters, LOB% fluctuations have a much greater effect.
FanGraphs provides this handy chart to help put LOB% numbers in context:
Jesse Chavez's LOB% in 2010 and 2012? 63.1% and 49.7% (!!!!!) respectively. In 2010, his luck with runners on base was somewhere between "poor" and "awful". In 2012, it was over 10% below awful. Fangraphs doesn't even have a term for how bad Jesse Chavez was with runners on base in 2012.
It seems that his awful numbers weren't nearly as bad as they might seem at first glace. I think there is no way of demonstrating this better than the following: Jesse Chavez's career ERA is now 5.57. His career xFIP, the best predictor of future ERA, is 4.27. Not great, but worlds bett