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WAR 2.1, Fixed Runs to Wins for Pitchers and More

Posted by admin on May 9, 2012

WAR 2.1, Baseball-Reference.com WAR Explained

As some noticed in our last update to WAR. Pitchers were being significantly bumped up in value. This was due primarily to a change in our runs to win calculation. After some consultation with noted, anonymous sabermetricians Tom Tango and Patriot, we worked out a more sophisticated approach that still accounts for the player's effect on the run environment, but doesn't overvalue the contribution of stellar pitchers. We've added a new page to run through the changes we've made when converting from runs to wins. Converting Runs to Wins.

There are a few other changes that have been made as well.

Version 2.1, May 2012

  • A major change to runs to win calculation. See our Runs to Wins Page for a full explanation. We now handle runs to wins calculations in an exact rather than an estimated way.
  • With the change in runs to wins calculation we can now display Wins Above Average, a related win-loss % and a related win-loss% for 162 games played. We've cleaned up some of the presentation in other ways as well.
  • Leverage Index adjustment is now only applied to relief pitchers.
  • Leverage Index used is now the LI at the time the reliever entered the game rather than the average LI for all of their plate appearances. This is weighted by number of batters faced.
  • Renamed Offensive WAR from afWAR back to oWAR. Note that oWAR + dWAR now double counts position, so adding them will not give WAR.
  • Added columns for Wins Above Average (WAA), waaW-L% (effectively a rate stat for WAR), and 162waaWL%. The first W-L% is the W-L% of an otherwise average facing an average team would have in games this player played in. 162waaWL% adds enough .500 record to account for a full 162 game season (which is most applicable to pitchers).
  • The adjustment for the difference in league starter and reliever ERA has been moved to the calculation of league average rather than the league replacement level.
  • BUG: Fixed a park factor bug. Pitcher opponent strength was not neutralized, so a park factor was being applied to a non-park adjusted number. Now the pitcher opponent strength is converted to a neutral environment, averaged for all opponents and then park adjusted based on a custom park factor for each pitcher based on the exact parks they pitched in.
  • Some feedback of version 2.0 we incorporated: Inside the Book and its readers helped immensely with the runs to wins issue.

This change has been rolled out to all of the pages. As always, your feedback is welcomed.

This entry was posted on Wednesday, May 9th, 2012 at 11:18 pm and is filed under Announcement, Baseball-Reference.com. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

6 Responses to “WAR 2.1, Fixed Runs to Wins for Pitchers and More”

  1. Overall I really like the new WAR, but I'm wondering why the "Defensive Runs Saved" numbers (DRS) aren't always the same in the "Fielding Table" part of a player's page and on the "WAR Table" part of a player's page. Isn't DRS the defensive metric baseball reference is using to calculate WAR now?

    The example I used for this via Twitter to the baseball reference account last light was Troy Tulowitzki. His DRS numbers for 2009, 2010, & 2011 are +13, +19, and +11 in the fielding part of his page. However, they are slightly lower and rank +11, +15 & +9 in the WAR table part of his page. There are some other examples too but that was the first one I noticed.

    Why isn't Tulowitzki's DRS number being used here?

    Any feedback would be greatly appreciated.

  2. Matt,

    I'm going to look at this today or tomorrow. Something is clearly wrong and we'll get it fixed.

  3. Regarding the runs to wins conversion, I don't understand why the ratio is different for WAA and WAR. The explanation page (http://www.baseball-reference.com/about/war_explained_runs_to_wins.shtml) doesn't tell me (and has different numbers for Halladay's 2011 season than his page does.)

    For Halladay in 2011, there is an 8:1 ratio of RAA to WAA, but a 9.18:1 ratio of RAR to WAR.

    Also, on the explanation page, you claim there were fewer runs scored in 1912 than in 1933, when in fact the opposite is true. You might want to move those years back by 3.

  4. I was wondering why Strasburg had dropped off the NL WAR leaderboard, when I checked the calculations on his player page I saw that he was only given credit for 26 IP instead of the actual 44. I don't know if this is an example of a wider systemic error, or peculiar to Strasburg.

  5. We had a build bug that will be fixed in a few minutes Sorry for the error.

  6. Any update on why the Defensive Runs Saved totals don't match the WAR totals for middle infielders?

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