UPDATE: This quote:
@nationals101 Does it include a quote saying it is my favorite stat?
— James O’Hara (@nextyeardc) May 6, 2013
Welcome to Get to Know a Stat! Once a Week (or so) I intend to take an advanced baseball statistic and present it to you in a way that’s understandable.
This week, I want to look at a stat called Weighted On Base Average, something mentioned by Court a few weeks ago in his Holding Court column. A lot of folks hold on to batting average as the end all/be all of comparing batters despite the fact that there are many other metrics to look at-often giving a more complete picture of what is going on.
To give you a basis for what I’m talking about, allow me to parrot some of the more insane arguments I’ve heard/read to start Steve Lombardozzi over Danny Espionsa at second base. Note: [Insert my usual disclaimer of love for Lombo as a utility player even if I disagree with the position he should be a starter]. The case for Steve Lombardozzi goes something like this:
- He’s just as good a fielder as Danny Espinosa [Not at all true, but we’ll deal with that another day]
- Danny Espinosa strikes out too much, and Steve Lombardozzi doesn’t strike out nearly as much
- About a week ago Danny Espinosa was only batting .155 (currently .185) and Lombardozzi was batting .365 (now .235)
- Danny Espinosa can’t hit with runners in scoring position, and gets no RBIs. Lombo is “scrappy” and “clutch.”
Now usually, I can go through the whole litany of reasons that is insane.
- You can start with the fact that Lombo hasn’t nearly had the plate appearances Espinosa has had (so it’s likely that his average will drop-which it did recently).
- You can point out that while Lombo doesn’t strikeout as much as Espinosa, he doesn’t draw walks (he has only one) which indicates maybe he doesn’t have a great eye, but just makes contact outside the zone (bad contact that leads to ground outs).
- You can also take a look at Total bases which is the total number of bases a player gets per hit (a HR is 4, Triple 3, Doubles 2, Singles 1). Espinosa’s total bases double that of Lombardozzi’s- meaning he’s getting much bigger hits than Lombo, who hits a lot of dribbler singles that squeak through.
You can do all that, and I can do all that, but it might be better to look at something come up with by Tom Tango called Weighted On Base Average (wOBA).
You may have heard the phrase “A Walk is as good as a hit?” Well, sometimes it is-but usually it isn’t. So while On Base Percentage and Batting Average looks at all hits and walks equally, wOBA “weights” the type of hit, because, well, some hits are better than others. The formula (as it appears on Wikipedia) if you please:
Those coefficients, those change yearly-so this is how the original formula look. The reason they change is because what happens each year when a player reaches base these different ways changes. Don’t over think it :) If you want, you can read all about it elsewhere; our purpose today is simply to understand what the formula suggests so we can read it accurately.
Getting a walk is different than getting hit by pitch, but neither is as good as getting a single or reaching base on error. For some reason (maybe based on how it historically affects the pitcher?) those four different ways of reaching just first base are valued differently. You’re more likely to score a run (or you’re being more helpful to your team anyway) from first if you hit a single or reached on error than if you walk or hit by pitch.
Doubles, Triples and Home Runs, obviously, all help more than getting to first base. Where possible you want folks to do that instead of just get to first, but getting to first is still very useful (and getting a double is not twice as good, nor is a triple thrice as good it turns out).
So wOBA tracks not just getting on base, but how you’re getting on base and then (using information from the current season) weights the importance of those hits as well.
Folks can then take wOBA and compare it to other players to get a better sense of who is a better hitter. It makes answering “would you prefer a slugger with a lower average, or a singles hitter who hits softly” a little more manageable, in my opinion.
You can also then take a look at Weighted Runs Created (wRC) to see how those wOBA averages turn into runs. wRC is a much more difficult actual formula to explain, so I leave it to you to go look at it if you want. Basically, you can use a players wOBA, the league average wOBA and average number of runs created per plate appearance and turn that into how many runs a player creates (rather than just how many runs he bats in, or runs he scores from the bases). Let’s take a look at some stats then for Player 1 and Player 2:
Without too much guess work, you could probably figure out who is who. And if you’re looking at things like average, Lombo looks much stronger (although, I hasten to add, that if you look at the last 9 games Danny has an identical batting average).
But if you’re at all convinced that not all hits are created equal, keep scrolling over and you’ll see that despite a .185 batting average, Danny Espinosa’s wOBA is .257. That’s still low for a second basemen (.300ish is average for a second basemen), but you have to remember Danny had a very rough April. If you look at his 2011 and 2012 wOBA you can see he matches up as slightly above average as a batting second basemen…despite all the Ks you worried so much about.
Steve Lombardozzi, allegedly, had a great April and he was super hot and the Nats needs to keep playing the hot hand-right? Yeah well, tell that to his .248 wOBA. When Steve Lombardozzi makes hits, even though he’s striking out less and has a better “average”, those hits don’t help or matter as much. wOBA says that Danny is the more valuable at bat. And that’s after an alleged quick start for Lombo.
Lombos 2011 and 2012 wOBA are also lower than Danny’s averages (and below those of an average second basemen)-so I don’t particularly understand where the idea that more at bats is going to help Lombo. This is who he is. His numbers are excellent for a utility bench player. The drop off isn’t huge from any particular player for a short period of time…but its there, and its real and its distinct.
The wRC numbers also play out the same way. Consistently, Danny hits are going to turn into runs (one way or the other) more often than Steve Lombardozzi hits will-and its consistent with last year which many people held out as an “awful” year for Danny Espinosa. It wasn’t, really.
So who do you want? The hot player who is creating less runs? Or the player who is just warming up and already creating more runs?
In many ways outs are more equal across the board than hits are. Opening up your mind to things beyond simply average and strikeouts is necessary to get a more complete picture of just how good (or bad) a hitter is.