New Season; New Stats (wOBA)

A lot of commonly used baseball statistics are not very useful, but show up again and again because of that thing called TRADITION.

I know. I know. Change is scary. I’m like that too (with a lot of things), but I promise we’ll go slowly and only introduce one new statistic per entry.

Before we go further along, I want to send my most sincere thanks to fellow UC Davis Aggie and Project Prospect Owner and Founder, Adam Foster. He has helped me along the path of discovery as far as statistics go. Also, special thanks to Bill James (we have not met, but I’ve read much of his writing) and many other baseball statisticians for making a positive impact on me. Trevor Kuss and I have also had some helpful discussions on the topic.

We’ll begin with wOBA, the abbreviation for “weighted On-Base Average”. First of all, let’s explore why this “wOBA” stat should be more useful than the more traditional batting average, on-base percentage, or OPS% (on base pct plus slugging percentage).

Batting average is not ideal, because its calculation is too basic. A batting average is strictly a player’s hits divided by his at-bats. Walks, hit-by-pitch, sacrifice bunts, and sacrifice flies are all excluded even though they help ones team. Furthermore, a home run or triple counts precisely the same as a single or double. The stat is clearly flawed.

On-base percentage is better, but again, a single or a walk counts exactly the same as a triple would. This is a major problem.

Slugging percentage rewards a player for getting more total bases. In other words, a home run is a lot better in terms of slugging percentage calculation than a single, but regardless, problems still persist. First of all, a walk is not rewarded in the stat. It’s simply disregarded. Also, the slugging percentage weights the home run as four times better than a single, but this clearly overestimates the impact of a home run.

For the above reasons and a couple unlisted ones, it would be better to start from scratch rather than to combine OBP and SLG% into OPS. Instead, we’ll use wOBA (weighted on-base average).

The formula for wOBA is as follows:

(.72 BB+ .75 HBP + .90 1B + .92 RBOE + 1.24 2B + 1.56 3B + 1.95 HR)/ PA

*RBOE refers to the numbers of times a player has reached base due to error. Plate appearances is of course denoted by “PA”.

Unfortunately, RBOE is nearly impossible to find so I will have to make my calculations without this data. Luckily, players do not reach base due to error very often, so it will hardly affect the final numbers.

Before we do this, keep in mind that according to most sources, a great hitter will reach .400 or higher, .340 is about average, and if one is below .300, he is likely a poor hitter. Ok. Let’s go!

*Keep in mind that these wOBAs would be slightly higher if RBOEs were included, but we’ll have to do without them.

Matt Kemp- 242.16/667= .363 (Above average, Good)

Andre Ethier- 256.2/685= .374 (Good)

Rafael Furcal- 215.44/680= .317 (Below average)

Russell Martin- 185.14/588= .315 (Below average)

NL MVP Albert Pujols- 322.26/700= .460 (Off the charts)

Tags: Adam Foster, Albert Pujols, Bill James, Dodgers, new stats, Project Prospect, traditional stats, Trevor Kuss, weaknesses, weighted on-base average, wOBA