Running 2017 MLB regular season thread

You still haven't really explained yourself regarding why you find ERA superior to FIP or xFIP. You've just kind of asserted it. And I would hardly say you've been proven "right" at this point, whatever "right" means.

Jon Lester, 2016
ERA: 2.44
FIP: 3.42
xFIP: 3.47
SIERA: 3.61

Jon Lester, 2017
ERA: 4.25
FIP: 3.97
xFIP: 3.74
SIERA: 3.98

Lester was a lucky SOB last year, pitching in front of a historically great defense. His ERA, at 2.44, was 1.17 runs better per game than his SIERA, which is like FIP on steroids, i.e. it doesn't assume the same out rate for every kind of batted ball.

Fast forward to this year, his ERA is at 4.25. But his SIERA is at 3.98. Now that's not great, though not out of line with prior seasons for Lester.

2008 - 4.15
2011 - 3.58
2012 - 4.01
2013 - 3.90
2016 - 3.61

Obviously, Lester's SIERA from last year was much more predictive of his performance this year than his ERA, which was largely a product of the Cubs defense.

For shits and giggles, I took a semi-random sampling of pitchers over the last five seasons, guys who have been rotation regulars over that entire course, to see if ERA or xFIP was more predictive of their performance the next season. A lot factors into this. For instance, their ERA may be stable because they are pitching in front of the same defense. And, in an era where we get so much information about batted balls that FIP is becoming semi-obsolete, xFIP may not quite capture isolated skills as well as something like SIERA or average exit velocity. Plus, we have the small sample size issue. It wasn't exactly the most scientific study ever conducted.

But this is what I went with, on the back of the napkin. The pitchers were Gio Gonzalez, Cole Hamels, Ricky Nolasco, Zack Greinke, and Johnny Cueto. I can type out the full results when I have more time later, but the bottom line was that for those pitchers, since 2011, xFIP was more predictive of the following season 16 times, ERA was more predictive 14 times. Where the difference between ERA and xFIP was more than 0.50 runs, FIP was more predictive seven times and ERA six times.

So largely playing in front of the same defense in a lot of cases (though some of these guys got traded over the course of the time period), xFIP outperformed ERA as predictive of a pitcher's future performance, though barely. (And just as a binary thing. I know this isn't the best method, mathematically, of figuring that out. Again, we're working on the back of the napkin here.)

Bottom line: Has Lester been as good as last year? No, he hasn't. But he wasn't as good as his ERA said he was last year, and he's not as bad as his ERA says he is this year, even with the ugly start the other day. Based upon his track record, the Cubs are basically getting what they expected from an aging Jon Lester when he signed this contract.

 

OH MY GOD ANOTHER MELTDOWN! ALERT THE MOD SQUAD!

 

Did you hear about the Spanish magician.

"On the count of three, I will disappear! Uno ... dos ..." *poof*

And with that, he disappeared without a tres.

 

Or not, I see.

 

Hey, I admit I was pissed. I had a 1,500-word post that got deleted. I didn't read the by-laws closely enough. If you go over 1,499 words, the post has to be about the Federal Reserve.

 

I was jokingly going to post this morning whether we should put the over/under on his return in days or hours.

You can't quit the site, DW--it's your crack and meth all rolled into one...

 

That is a whole lot of stuff to cover up the part in bold. Lester is clearly part of the problem. He has been far less effective than he was last year.

I actually have explained what I like about ERA many times, but don't let such facts get in the way of a good rant. Looks like you were obsessing over this during your latest absence. Also looks like you were at the very least unclear, if not misleading in that last post comment earlier.

Welcome back. Glad you finally admit what I've been saying about Lester all along, even though you buried it under an attempt to justify your previous position.

 

That's nebulous, but I don't think a 0.30 change in xFIP and a 0.37 change in SIERA qualifies as "far less effective." Your mileage may vary. Every peripheral statistic indicates that his skills are largely the same as last year. Until his last start, they were almost dead-on.

I don't feel like you have. You've said that you prefer ERA because it's "what happened." But I could say the same thing about the skills-based statistics. Really, they describe "what happened" more effectively than ERA, which incorporates defense and random sequencing.

Why do you prefer ERA when other statistics are provably more predictive and, it follows, more accurately capture pitcher performance?

This part is exceedingly uninteresting to me. I don't want to talk about myself or my motives. Let's stick to the actual discussion/debate.

I don't know what this has to do with Jon Lester.

Thanks, bro.

Bingo!

 

Your unclear and somewhat misleading post on another topic goes to credibility. So does the bit about you focusing your off time on this. I really don't care if you don't like it or not.

I have explained my point regarding ERA many times. That you don't like the answer does not make it insufficient.

If I cared about SIERRA as much as you do, you might have a point regarding Lester's performance. I do not. He is clearly far less effective this year than he was last year. You insisted he is not a part of the Cubs' problem this year and that is clearly incorrect. Your attempts to distract from that don't work.

Bullshit like bingo is the hiding place of posters who know they are losing. No surprise at all to see you there.

 

It really, really doesn't. Evidence-based arguments like this either stand or fall on their own merits.

But your explanation begs the question: Why does your "what happened" trump my "what happened" when my "what happened" is more predictive than yours?

This is like "believing" in evolution or climate change. You don't get to decide this. SIERA is more provably more predictive of future performance than ERA.

He's not. The Cubs defense is.

This part bores me.

 

Not true at all. People get sick of beating their heads against the wall arguing with you.

Why do you think ERA is more important than SIERRA?