Archive for January, 2011

What Is the FanGraphs Library, and How Do I Use It?

After Dave Cameron’s introduction yesterday, I wanted to take a brief minute to explain the purpose and goal of the Library for those that haven’t seen it before. And before I begin, thanks to everyone for the kind words yesterday about the Library.

The Saber Library was initially created around a year ago, in response to some criticism we’d received at DRaysBay. Many (most) of our columns there deal with advanced stats, like the work done here on FanGraphs, yet many readers were having a tough time accessing the information and learning about sabermetrics. We’d tried running a saber primer or two, yet those could never be comprehensive enough to cover everything that needed to be said. Readers wanted to learn, but didn’t have a place to go to do so.

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Statistic Percentile Charts

How awesome is this chart? It’s simple, easy to understand, and imparts a swath of information all at once. I had no idea what league-average Isolate Power (ISO) was until now, but bam, there it is. This, my friends, is a thing of beauty. Until I saw this chart, I had no idea I needed all this information, but now that I’ve seen it, I want more.

I suppose I shouldn’t be surprised: this work of genius was created by Lee Panas, the writer at Tiger Tales and the author of “Beyond Batting Average”, a concise, well written book geared toward introducing everyday baseball fans to sabermetric statistics and analysis. It’s a great book and I recommend it thoroughly (although in the spirit of full disclosure, I must admit that I have a soft spot for Lee: not only am I a fellow saber-ed nut, but like Lee, I’m forced to root for my favorite ball team from afar, stuck in the wintery hellscapes of New England).

But I’m not writing this article as a book review (you can find those elsewhere); I’m writing because of that beautiful graphic up above. One of the complaints I hear most frequently from saber-newbies is that while they want to use these new statistics, they have no idea if the numbers they’re seeing are good or bad. Is a .320 wOBA good? Exactly how bad is a -5 UZR? I know it’s bad, but is it only mildly bad or tear-your-eyes-out bad? And what, pray tell, does a 4.00 tERA mean? It’s one thing to understand the theory behind the statistic, but sometimes understanding its scale can be just as challenging.

And so, I’ve taken Lee’s lead and included similar charts on each of the statistic pages here in the Library. The league-average rates are all accurate, and I’ve estimated percentiles based on the scores of all batters with more than 400 PA and pitchers with more than 90 IP. These percentiles may not be 100% accurate in all instances, but they are close enough to work as estimates in order to provide context.

Thanks again to Lee for the inspiration. If you like the charts, go check out some of his work.

Suggestions and Questions

Now that the new version of the Saber Library is up and running, I’d like this to be more than just a reference site: I want this to be an area where people can come and have their questions about sabermetrics answered. If you ever have any questions about a sabermetric principle or statistic, please reach out to me on Twitter (@steveslow) or by emailing the Saber Library’s mailbox: saberlibrary at

I can’t promise that I’ll give you an in-depth answer to every question, but at the very least, I’ll do my best to direct you to the right place to find the information you’re seeking. Also, if I get enough questions, I’ll start a “mailbag” feature and answer some commonly asked questions in a weekly post. I’m no expert on sabermetrics – far from it – but we have many knowledgeable writers on staff here at FanGraphs, so if I don’t know the answer to a question, I’ll be sure to find someone else who does.

Also, feel free to contact me with the Saber Library’s email address if you notice any factual mistakes with the Library (like I said, I’m no expert), you have any suggestions for the site, or you have any cool content / links to pass along. There are many writers out there making saber primers, filming introductory videos, and creating educational visuals, and I want the Library to help promote those efforts.

In other words, if you have any questions, suggestions, or cool links, hit me up.

Welcome to the Library!

Really, the Saber Library should never have existed. It took way too much time to create, cost me out-of-pocket money, was tedious as hell, had no tangible reward, and took away time from what I really should have been doing: finding a job. It was a project that most people in their right minds would never contemplate doing. Thankfully, though, I’m stupid.

When combined with large doses of boredom and time, stupidity can be a dangerous thing: a perfect storm for mayhem. In the ninth grade, my best friend experienced a particularly brutal convergence of these three things in bio lab one day, and stuck tweezers in the electrical socket to “…see what would happen”. Sparky eventually escaped his legacy by doing something even more stupid (breaking his leg during a chess match),  but so far, I haven’t been so lucky. Instead, I got to re-edit this entire thing for all you here at FanGraphs. Am I a sucker or what?

Thankfully, though, there are lots of smart people out there doing smart things that’s I’ve been able to steal from. Bradley Woodrum’s introduction to sabermetrics videos? Swipe! Graham MacAree’s incredible Saber 101 series? Stolen. Visuals from Justin Bopp at Beyond the Boxscore? Really, this is all too easy. Everyone’s been very gracious and willing to share, which has turned this site into a regular hodgepodge of smart things contributed by smart people. Trust me, I’m just as surprised as everyone else.

The Saber Library is now almost a year old and it’s here at FanGraphs to stay. I’ll be updating pages as FanGraphs changes, adding new statistics while changing the information on old ones, and I hope to make this a living, breathing resource. Consider it your Hitchhiker’s Guide to navigating the universe of sabermetrics (see what I did there?). While the math may be confusing and the Book Blog may give you a headache, this site is here to tell you “DON’T PANIC!” Things are not as complicated as they seem, and you don’t need to understand multivariable calculus to understand sabermetrics.

In the Library, you’ll find individual pages for nearly every statistic housed here at FanGraphs, along with a selection of primers on important sabermetrics concepts. We’ll also be using this space as a separate blog on FanGraphs (á la NotGraphs and RotoGraphs) and we’ll be writing articles geared toward helping people understand statistics. This space will (likely) not be updated as often as the other FanGraphs blogs, but we’ll see how this space develops.

And so, enjoy! Tour through the Library, learn something new, and whatever you do, keep those tweezers in your medicine cabinet.