Sabermetric Library
Dave · February 22, 2010 at 9:52 am · Filed Under Mariners
A month or so ago, I posted a link to the Lookout Landing thread that categorized and linked to information on most of the different sabermetric numbers out there. Well, now, a couple of Rays fans have taken it up a notch – The Sabermetric Library. If you’re new to the site and are intimidated by the numbers we’re throwing around, you now have a nice, easy place to get an overview of what they are, with links to more helpful articles written elsewhere. Here’s wOBA, for instance.
It’s Sabermetrics 101, and it’s long overdue.
Also of interest is the “Sabermetrics 101” series Graham is doing over at LL.
why do we scale wOBA to OBP? The only value I see is that it makes it easier to explain what is good, but it doesn’t do that completely. All we’ve done when multiple all the run-values by 1.15 is make the means of OBP and wOBA equal, but this doesn’t make the variance equal. So, while I can say the average of one is about the average of the other, it doesn’t really tell me whether a .400 wOBA is better or worse than a .400 OBP, and I imagine this is a detail that is lost on most who read about it.
Plus, they measure different things, so there’s two things I’d want to know about a .400 wOBA relative to a .400 OBP : (1) what percentile is a .400 wOBA and a .400 OBP? and (2) which is actually more valuable?
We first multiply by 1.15 to create “something people can understand”, but then have to reverse that back out in order to get to things like runs-above-average, runs above replacement, etc. I won’t throw out credentials, but I’m pretty good at math… and it wasn’t until I just followed multiple links that I realized that the 1.15 was JUST a scaling factor that we both multiplied and divided by.
We throw around a scaled number, which supposedly makes it easier to explain to people. But the cost is that it makes it harder to explain the RAA calculation.
just my 2 cents.
Cool. Should be required reading. What I love about it is how much context is given with each stat.
But let’s hope, for the sake of his own self-esteem, that Yuni never discovers that site.
My favorite part about the link to the wOBA page is that it shows Betancourt’s wOBA and how it is 64 points below the league average. It just makes me smile for some reason.
I’ve only read the wOBA entry; the text was clear, easy to understand, and provided context. So good job there.
Not so good: wasn’t wOBA created by Tom Tango? I.e. one glaring omission is citations, and credit for who did what work (and when).
In a similar vein: on the home page, I have a feeling that they didn’t get permission from the Schulz estate to use the Peanuts carton.
Edgar’s career wOBA, by the way, was .405. I’m just saying….
@MKT Thanks for the feedback. On some pages I have given credit to the creators of said statistic, but on others I forgot. I’ll be sure to get back and put that in there since while it’s not essential info for newbies, it’s nice to at least tack in there somewhere. And yes, I didn’t get permission from the Schulz estate, but I’m not planning on making any money off the site so I didn’t think it was that big an issue. Then again, I could be wrong. Anyway, I just thought it was fun, but it probably won’t stay up too long.
@Dave Thanks for the props.
loveMeSomeStats: My full response is here.
Thanks for the post. Having that link will help many of us get up to speed on Sabermetrics (especially me!).
Thank you for directing to this. Hopefully it will be helpful to me as at least a way to understand why the stat is being used, if not necessarily the stat itself.
@ Steve Slow
The issue isn’t always money, it’s often whether the third party use is consistent with the image the copyright holder wants to project. (See “The Other Family” spoof of “Family Circus” or the “Bert Is Evil” spoof of the Sesame Street character.) In your case, that use is perfectly appropriate and the estate’s attorneys will find better ways to spend their time.
Thanks this is really helpful.
tangotiger your link failed
I am glad for this, but disappointed that it didn’t exist years ago. Over the past six years I’ve managed to put together bits and pieces of SABR analysis to reach the point where I understand all the basics, more or less; it certainly would have benefited me if I’d had been able to get all the information in one place, at once. Of course, having learned analysis in bits and pieces, this still benefits people like me a lot, because we tend to have holes in our knowledge, and this kind of resource will make it a lot easier to fill those in.
BTW, Tango’s link worked for me from both home and office.