Wins Above Replacement (WAR) is a stat that combines measures of all aspects of a player’s value to create one total figure that expresses the player’s value in terms of wins provided to his team:
- contains measures of both offensive and defensive value for non-pitchers
- is expressed in terms of wins
- uses a replacement-level baseline that is at some point below average
- measures value provided by a player as opposed to the true talent or ability of the player
DRB :
The batting component of WAR consists of park-adjusting wRAA(runs above average)
wOBA (weighted on-base average) : wOBA consists of using linear weights of each type of event where a batter reaches base successfully relative to the total plate appearances.
By using linear weights to quantify offense and defense, it is possible to determine the value of a player above replacement level. WAR (Wins Above Replacement) is the statistic that represents this idea. It can be expressed in terms of wins and dollar value. There are 6 components of batter’s WAR.
The next component is Fielding runs. This is based on UZR (more info here) and is also expressed as a run value. A UZR of 5 means that player saved his team 5 runs above what the average player playing that position did. Remember, a run saved is as good as a run earned.
The 3rd component is the Positional adjustment. It should be obvious that, in baseball, certain positions are easier to play than others. Great hitting SS are harder to find than great hitting 1B. So, we have to adjust for that.
The 4th part of WAR is the Replacement runs component. What this is is the expected amount of production from a team full of Triple-A call-ups, the proverbial “AAAA player.” The number of runs a replacement level player should contribute is 20 over 600 Plate Appearances. So, this means that players who exceed 600 PAs get credit for being on the field more, while those who don’t reach 600 PAs don’t earn the full 20 runs of replacement
Batting (wRAA) + Fielding (UZR) + Positional adjustment + Replacement value = RAR (Runs Above Replacement). In order to get this number into Wins, the math is simple; just divide by 10. So, if a player is worth 40 runs, they are worth 4 wins.
Dollars – The amount of money a player’s WAR would be worth that season on the open market based on league average. For example: Albert Pujols had a WAR of 8.4 in 2009, which was worth $38 Million based on the average cost of a win in 09 (4.52MM per win).
offense + defense + position + replacement level
