Saber 101: The search for the perfect offensive statistic

I've been told that the first paragraph of a post is the most important in terms of search engine keywords, so just bear with me for a moment: wRC+ is a sabermetrics statistic, based on the runs created stat invented by Bill James, a stat that the Tigers' General Manager Dave Dombrowski surely knows about, and speaking of Tigers, I believe Justin Verlander (who will soon be available as a selection for your FanDuel fantasy lineups) is still dating Kate Upton, who has been doing Game of War ads, and who was a victim of cell phone hacking which resulted in pictures of her boobs being downloaded on many laptops.

Now that we've taken care of that, let's talk about batting statistics. As a well-known orator once said:

"Starting a blog post with a quote is so cliche, man, I really wish you'd get more creative." (Albert Einstein)

On the eighth day of creation, the Baseball Gods crammed wads of chewing tobacco into their mouths, adjusted their protective cups, and said, "let there be Batting Average, that thou may verily knowest who upon the earth doth suck, and who doth light 'mups,' that thy All Star voting choices may be pure and spotless and admired by all."

And for a long time, we, the fans, were completely happy with batting average. But then Little League coaches everywhere began to say things like, "rub some dirt on it and walk it off," "don't aim, just play catch with your catcher out there," "you've got your glove on the wrong hand again," and most importantly, "a hit's as good as a walk."

It was that last bit of truth that did us in, collectively, and we realized that batting average gave the batter no credit for patient at-bats leading to walks. Indeed, batting average, we discovered, would not even acknowledge a base-on-balls as a legitimate at-bat, and that's when Brad Pitt decided to launch the on-base-percentage (OBP) revolution.

Then Jim Leyland got irritated and said, "I'm a big slugging-percentage guy, not that on-base shit. A lot of guys can get on base. I want a guy who's gonna knock 'em in" (seriously, he said that, it's in Tales from the Detroit Tigers Dugout), and more people would have argued with him, except that he was eating fistfuls of lit Marlboros right out of the jar and looking pretty intimidating, so a compromise was found: just add OBP to slugging percentage and call it OPS!

If you're not a big fan of advanced metrics, I get it. Batting average, RBIs, and home runs are like your old Uncle Mort who's maybe a little off his rocker and says weird things at family gatherings now, but he did single-handedly save the family business back in the 1940's, so dammit, you're going to show him some respect no matter how doddering and demented he gets. But OPS is a nice middle ground, and it does a decent job of summing up a batter's performance, so maybe take that home as a souvenir and see how it fits.

Where OPS falls a bit short is that it relies on slugging percentage, and the guys in the lab have discovered that slugging percentage doesn't tell us what we really want to know. (This is about to get a bit hairy, so now's your last chance to grab an OPS t-shirt and get off the bus -- say hello to Uncle Mort for me.)

Slugging percentage is really just a measure of how many bases a batter reaches in any given at-bat. A single is worth one, a double is worth two, and so on. But as Geekmaster General Bill James said, "exponents tangential to the Pythagorean numerator, leading to the cofactor squared delta bravo, so obviously modulus quotient algorithm, you cretins." Translated: a batter's job is to create runs, so that's what we should be measuring.

The result was the Runs Created statistic, and by this point the Baseball Gods were getting irritable and saying things like, "thou shalt not put too much pine tar on a bat, don't ask us why, and henceforth, tampering with a baseball shall be considered worse than attempting to murder a batter by throwing 95 MPH fastballs at his head."

Runs Created streamlined a batter's offensive stats (hits, walks, caught stealing, etc.) and distilled them into one number. This made it possible to say, with total confidence, "Miguel Cabrera is pretty good," and then after your friend smacked your head and said, "no shit, Stephen Hawking, he won the Triple Crown," you could say, "ah, but did you know he was worth 139 runs created that year?"

Do you see the value in Runs Created as a stat, and think, "I might actually start using that"? Well, too bad, because it's been made obsolete by wRC+, or "weighted runs created plus."

(That's advanced metrics for you: the minute you find a good one, the number-crunchers say, "actually, we just discovered that this stat is not accurate, and in fact, is alleged to have caused poverty in several third world countries, so if you ever use it again, you're basically Hitler.")

The wRC+ stat takes all of those run-creating events (walks, singles, etc.) and "weights" them by giving them more realistic values based on history (e.g., a single is, historically, worth about half-a-run), then makes further adjustments for league and ballpark factors (that's the "plus").

The nice thing about wRC+ is that it's baselined at 100, so if a player has a wRC+ of 150, you can say he creates 50 more runs than the average player. The not-so-nice thing about wRC+, at least as of this writing, is that it's only available at fangraphs.com, so if you prefer baseball-reference.com, tough luck.

Let's take a look at wRC+ in action, and then you really need to go finish mowing the lawn. Here are the top 15 Tigers batters of the past 50 years, ranked by wRC+:

One thing that stands out: Al Kaline's 1967 season ranks above Alan Trammell's 1987 season, despite Trammell's .343 batting average being well above Kaline's .308, and despite their other stats being relatively equal. This is where you can see some of the wRC+ adjustments at work, because Trammell played at a time when the league average OPS was .759, while Kaline played when the average OPS was .654 -- to name just one factor.

This also illustrates the weakness of batting average as a stand-alone stat, because Cecil Fielder only hit .277 in 1990, and yet his wRC+ of 165 puts him in the Top Ten list of the last 50 years. Why? Because he had that incredibly high .377 on-base percentage, and he hit 51 home runs that year, one of the most valuable "run-creation events" on the weighted list.

So that's wRC+, and you can forget everything I've said and still find use for it if you just remember that 100 is average, and 200 is Miguel Cabrera territory.

Questions for Discussion