wRAA
Weighted Runs Above Average (wRAA) measures the number of offensive runs a player contributes to their team compared to the average player. How much offensive value did Evan Longoria contribute to his team in 2009? With wRAA, we can answer that question: 28.3 runs above average. A wRAA of zero is league-average, so a positive wRAA value denotes above-average performance and a negative wRAA denotes below-average performance. This is also a counting statistic (like RBIs), so players accrue more (or fewer) runs as they play.
Calculating wRAA is simple if you have a player’s wOBA value: subtract the league average wOBA from your player’s wOBA, divide by the wOBA scale coefficient (1.26 for 2011), and multiply that result by how many plate appearances the player received.
wRAA = ((wOBA – league wOBA) / wOBA scale) × PA
You can find “wOBA scale” values for any year from 1871-2010 here, and league-average wOBA for every year can be found on the FanGraphs leaderboards. The exact wOBA scale value varies on a year-to-year basis in order to set wOBA on the same scale as league-average OBP. Also, if you’re feeling ambitious, it’s possible to calculate wRAA using linear weights.
Context:
Please note that the following chart is meant as an estimate. No matter the year, this statistic will always have 0 wRAA as league-average.
| Rating | wRAA |
|---|---|
| Excellent | 40 |
| Great | 20 |
| Above Average | 10 |
| Average | 0 |
| Below Average | -5 |
| Poor | -10 |
| Awful | -20 |
Things to Remember:
● wRAA is league adjusted, meaning you can use it to compare players from different leagues and years.
● When calculating Wins Above Replacement (WAR), wRAA is used to represent offensive ability. Ten wRAA is equal to +1 win.
Links for Further Reading:
Steve is the editor-in-chief of DRaysBay and the keeper of the FanGraphs Library. You can follow him on Twitter at @steveslow.
how would u do this in excel?
It’s simple as long as you figure out the wOBA, and know the league average wOBA. In my spreadsheet, I have it as =((AG7-AH7)/1.15)*E7, where AG7 is the actual wOBA; AH7 is the league average wOBA; and E7 is PA. Obviously, your cells could be different depending on what you have in your spreadsheet.
Is there an alternate version of this statistic that adjusts for the number of games a given player has played in a season? I know this site keeps tracks of UZR/150, so I couldn’t help but wonder if there was an equivalent statistic (wRAA/150, I suppose) that allows you to extrapolate a player’s current wRAA to a full season’s worth of playing time/compare wRAA of players with a substantially diffeent number of at bats.
Wouldn’t that basically just be wOBA?
Stupid question here- trying to really understand all these number.
Why dividide by 1.15?
I have the same question as Paul.
Why divide by 1.15? What does that constant mean?
Will it ever change? Is there a formula to calculate it?
Does anyone know why a players Total wRAA doesn’t add up to his (wRAA vs LHP) and (wRAA vs RHP)? For some players it is almost exact, but for others such as Ichiro Suzuki it is far off. In 2011 his total wRAA was -15.5. Against LHP his wRAA was -4.4 and against RHP his wRAA was -16.5. Why isn’t his total wRAA -20.9? Also, under the VALUE tab his BATTING value is -12.2. I’m trying to estimate a hitters BATTING value vsLHP and vsRHP since it isn’t listed on the site. I thought extrapolating using the wRAA for LH… Read more »
You divide by 1.15 because that’s the number you multiple base OBA to scale it up to a number similar to OBP. It’s just a scaling factor to have OBA easily comparable to OBP. Thus, to convert back to wRAA, you must first scale it back down (divide by 1.15) to convert to the actual runs above average.
typo; multiple=multiply.
So, the equation for wOBA should include this scale constant then? Because in the entry here on Fangraphs it doesn’t.