Running 2017 MLB regular season thread

Actually, you used performance this year to justify your argument from about Arrieta's performance last season. You also claimed that you kept going on and on about Arrieta while ignoring all of the Cubs other problems early in the season because it was just so important. When I brought up Lester's decline, you said you weren't concerned. Now Arrieta has better numbers than Lester. That amuses me.

All this fits into your practice of choosing whatever sample size fits the argument you are trying to make at the moment, intellectual honesty be damned.

 

You're a fool.

 

You put way too much emphasis on projected stats like xFIP or DIPS for a pitcher's performance within a season. ERA is a measure of what did happen. You want to include unearned runs? Fine. I understand that ERA can be influenced by luck, sequencing, and team defense, but we don't know to what level it has been unless we are going to go through every batter faced by a pitcher. As a tool for prediction, those stats are fine to me, but don't dismiss ERA as a measure of what a pitcher has done.

 

This just begs questions. You are declaring ERA a useful measure, albeit more diplomatically than the other guy.

Why?

And it's not just DIPS and xFIP. I've looked at batted ball profiles, etc.

 

Your choice of article there might answer your question.

 

Is this supposed to be another shining example of talking baseball?

You were wrong about Lester. You were wrong about McCutchen. It may turn out that you were wrong to drag the Arrieta thing into this year now that he seems to be coming around. I'm sorry all of that troubles you so much.

 

What I am saying is ERA measures actual performance, rather than some hypothetical "what should have happened based on what happens on average among other pitchers." We don't know why ERA and xFIP diverge for any individual pitcher during a season. We may have clues, like team defensive measurements, but to cling to the idea that ERA is something to be ignored is silly.

 

Hmmmm ... not sure I agree. It measures a single byproduct of actual performance, alloyed with a lot of randomness.

 

ERA is as contrived a measure as any other, in that what constitutes an "earned run" -- and which pitcher it is attributed to -- is entirely the result of a long-standing practice rather than some empirical fact.

 

I argue that "what happened" is better reflected in objective measures separated from randomness or team defense. K rate. BB rate. Batted ball profile. Average exit velocity. Barrel pct.

That' "what happened." What the pitcher can control.

 

No, it measures how often a pitcher let a runner cross home plate, which is the fundamental point of the game. Yes, league and park factors can skew ERA, but that has been addressed. These extrapolated stats are just hypothetical measurements. Nobody can say with any certainty why there is any divergence between ERA and xFIP for a single pitcher in a single season. ERA is a measure of what a pitcher is supposed to do, not let the other team score. That's all that matters over the course of a season. If you want to say Joe Blowe cannot do it next year, fine. It doesn't mean he didn't do it this year.

 

Although I suspect that ERA correlates very strongly with ostensibly better measures, the whole "what happened" bromide irritates me. Pitcher A walks a batter and then is relieved. His replacement, B, promptly gives up a tater, thus (typically) laying an earned run on Pitcher A. Both are charged with the same event: Giving up an earned run. So, yeah, ERA totally measures actual performance.