What is WAR?

Wins Above Replacement (WAR) is an attempt by the sabermetric baseball community to summarize a player’s total contributions to their team in one statistic. You should always use more than one metric at a time when evaluating players, but WAR is pretty darn all-inclusive and provides a handy reference point. WAR basically looks at a player and asks the question, “If this player got injured and their team had to replace them with a minor leaguer or someone from their bench, how much value would the team be losing?” This value is expressed in a wins format, so we could say that Player X is worth +6.3 wins to their team while Player Y is only worth +3.5 wins.

Calculating WAR is simpler than you’d think. If you want the detailed (yet very understandable) version, check out the links at the bottom of the page; Dave Cameron does a good job of walking through the process step-by-step. The short answer, though, is that as follows:

● Offensive players – Take wRAA, UBR & wSB, and UZR (which express offensive, base running, and defensive value in runs above average) and add them together. Add in a positional adjustment, since some positions are tougher to play than others, and then convert the numbers so that they’re not based on league average, but on replacement level (which is the value a team would lose if they had to replace that player with a “replacement” player – a minor leaguer or someone from the waiver wire). Convert the run value to wins (10 runs = 1 win) and voila, finished!

● Pitchers – Where offensive WAR used wRAA and UZR, pitching WAR uses FIP. Based on how many innings a pitcher threw, FIP is turned into runs form, converted to represent value above replacement level, and is then converted from runs to wins.

WAR is available in two places: FanGraphs (fWAR) and Baseball-Reference (rWAR). Both statistics use the same framework and calculate replacement level the same, but use different ways of calculating offensive, defensive, and pitching value, so their results differ slightly. All the information provided on these pages refers to fWAR, unless otherwise specified.

Context:

League-average WAR rates vary. An average full-time position player is worth +2 WAR, while average bench players contribute much less (typically less than +1 WAR). Average starting pitchers also are worth around +2 WAR, while relief pitchers are considered superb if they crack +1 WAR.

For position players and starting pitchers, here is a good rule-of-thumb chart:

Scrub 0-1 WAR
Role Player 1-2 WAR
Solid Starter 2-3 WAR
Good Player 3-4 WAR
All-Star 4-5 WAR
Superstar 5-6 WAR
MVP 6+ WAR

Also, here’s a breakdown of all the players in baseball in 2010, courtesy of Justin Bopp from Beyond the Boxscore.

Things to Remember:

● Since there is no UZR data for catchers, the fielding component for catcher fWAR is calculated using two parts: the Stolen Base Runs Saved (rSB) metric from the Fielding Bible, and Runs saved from Passed Pitches (RPP). This accounts for a large portion of a catcher’s value, although pitch framing is not yet included in WAR.

● WAR is context, league, and park neutral. This means you can use WAR to compare players between years, leagues, and teams.

● It is possible to have a negative WAR. In fact, the worst fWAR any player has had since 2002 is Neifi Perez from the Royals, who posted an incredible -3.1 wins in 2002.

Links for Further Reading:

Intro to WAR – Big League Stew

Background on WAR – Offense

Background on WAR – Pitching

Common Misconceptions – The Book Blog

Simple WAR Calculator – Wahoo’s On First

wOBA to WAR Conversion – Beyond the Boxscore