As I walk down the winding path in the Twins area of the MLB Internet prairie, I have noticed a rapid change of opinion with reliever Ron Mahay. Two weeks ago, Mahay was sporting a 0.00 ERA with a 10/1 strikeout to walk ratio in 9 1/3 innings. However, it seems like his last three outings have erased that optimism. Seven earned runs and two home runs in 2 1/3 innings turned his excellent 0.00 ERA into a replacement-level 5.40 ERA. Because of this sudden change, I have seen several people on Twitter demand that he be designated for assignment. Is this really fair, though?
As I already mentioned, Mahay currently has a 5.40 ERA. If we look at his FIP, it’s a respectable 3.62, and Mahay’s xFIP is a very good 2.57. Now what is xFIP, you might ask? I left a link for the calculation of FIP when I discussed Brian Duensing, and xFIP is very similar, except the home run component in the calculation is normalized to the league average. In the Duensing post, I also mentioned how the average home run per fly ball is around 10%. Right now, Mahay’s HR/FB is double that, at 20% (2 home runs, 10 fly balls). If that 20% was the league average of 10%, Mahay would have an ERA closer to 2.57 than his current 5.40.
Not impressed? Mahay’s opponent’s batting average is .251, which is slightly above average. As I said before, he also has 13 strikeouts and 2 walks in 11 2/3 innings pitched. He’s had some bad outings lately, but those appearances do not carry any more weight than the scoreless innings Mahay pitched earlier in the season, and they are not true indicators of how he’ll perform for the rest of the year. He’s just fine, and there’s no reason why he should be designated for assignment.