OPS, wOBA and the BBM Total Offense Formula

First, let’s define our terms. OPS stands for on-base plus slugging. It is the combination of a player’s on-base percentage (OBP) and their slugging percentage (SLG). For many fantasy owners, it is the most convenient way measure players against each other since it values many the variables used in fantasy resolution formulas. wOBA stands for weighted on-base average. This is a statistic that was created by Tom Tango and presented in “The Book: Playing the Percentages in Baseball”. Tom makes the case that OPS is not an accurate reflection of the true run production of a player. By analyzing “linear weights” or the contribution that a single, double, etc. makes toward a run being produced, he devised a formula that calculates wOBA. This new statistic is has a similar scale to the more traditional OBP (see article). Lastly, the BBM Total Offense formula is the fantasy resolution formula used by Baseball Manager (BBM) to calculate offensive runs produced during daily head-to-head games (see BBM guide).

In order to figure out which stat is the best at projecting runs, I calculate each stat for the top 300 players in 2011. I then converted the rates stats (OPS and wOBA) into counting stats by multiplying them by total plate appearances. I ran the numbers through a correlation function. The results are shown below.





Runs (R)




As you can see, the correlations are all over 90%. However, the converted numbers for weighted on based average seems to have the best correlation to actual runs scored by the top 300 players in 2011. It is important to note that none of these formulas include runs as a component of the formula. Thus, the variables are all completely independent.

For completeness, I ran the same correlation as above against my projection data from last year and actual runs produced. The results are outlined below.





Runs (R)




I was surprised that the BBM total offense formula had a better correlation than either projected wOBA or projected OPS. I had expected the correlations shown with 2011 actuals to extend to projected numbers. My immediate concern was that the results were caused by some anomaly within my 2011 projections so I decided to run the same calculations using published Marcel projections. Those numbers are outlined below.





Runs (R)




As you can see, the calculations using Marcel projections also show BBM total offense formula having a better correlation than either projected wOBA or projected OPS.

You may ask, “Why do you care”? That is a very valid question. Besides the fact that I am a geek and like to analyze things, I was trying to figure out if there was a summative hitting statistic that I could focus on as I approach my fantasy baseball draft. Most of the people in Baseball Manager tend to focus on OPS. When I read the detail regarding wOBA, I thought I might have found the Holy Grail for hitter performance evaluation. And, it does have the highest correlation to actual runs scored when looking at actual season results. To my surprise, the actual total offensive formula used in my own fantasy leagues was better with preseason projections. Thus, I’m going to use the actual BBM formula against my projections on draft day.

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