What is WAR?

In the baseball community, there are plenty of reasons to evaluate the value of a player. Among them are free-agent signings, trading for a player, awards voting, and voting for the Hall of Fame.

However, the volume of different publicly available stats has become overwhelming. It can create confusion as to which ones are most effective for evaluating.

Wins Above Replacement (WAR) applies weights to each part of a player’s contributions and compiles it into a formula. It translate a player’s work directly into “wins” that the individual has produced compared to what a “replacement” from the bench or minor leagues would do under the same circumstances. WAR is applicable to both pitchers and position players.

It’s a concise method for evaluating a player’s season or career, but by no means lazy.

Rather than skimming past a position player’s slash line (batting average/on-base percentage/slugging percentage), WAR goes beyond that. Here’s the full formula considered during FanGraphs’ calculations:

WAR = (Batting Runs + Base Running Runs + Fielding Runs + Positional Adjustment + League Adjustment + Replacement Runs) / (Runs Per Win)

Traditionally, pitchers have been judged by their individual wins and earned run average. That doesn’t come close to painting the whole picture. Once again, FanGraphs has a more satisfying way to evaluate:

WAR = [[([(League “FIP” – “FIP”) / Pitcher Specific Runs Per Win] + Replacement Level) * (IP/9)] * Leverage Multiplier for Relievers] + League Correction

A huge component that people tend to overlook is ballpark factors. Not every stadium is the same in terms of size or climatic conditions.

For example, Marlins Park is unnecessarily big while Coors Field is a thin-aired offensive paradise. These tangible differences are applied to the weights of each result, so a home run in Marlins Park is more valuable than it would be in Coors Field. Whatever the raw results, WAR attempts to put them in the proper context.

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While having good statistics all around is important, some of the contributions made by a player are simply more valuable to winning games than others. Bill James, a pioneer of the sabermetrics movement, had this to say about why each factor must be weighted appropriately:

On the other hand, WAR is imperfect. There are two major websites that calculate WAR: FanGraphs (fWAR) and Baseball Reference (bWAR). They differ slightly in their weights and calculations.

Take Marlins rookie outfielder Lewis Brinson, for example. His fWAR is -0.8, but his bWAR is 0.2 in 2018, a full win difference in just a half-season of major league performance. That’s why it is important to distinguish between the two sources.

Also, because WAR is an approximation, you cannot definitively say that one player is “better” than another when the margin between them is narrow. So far this season, Brian Anderson has a 3.0 fWAR this season and Starlin Castro has a 2.3 fWAR. They are 0.7 wins apart from each other, but that could change in just a handful of plate appearances.

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All-Star J.T. Realmuto, meanwhile, has separated himself into another tier. His 4.0 fWAR leads the Marlins this season despite a brief stint on the disabled list. When you consider Realmuto’s diverse skill set and watch the games, it is quite obvious that he provides more value to the team than Anderson or Castro.

That leads me to another issue—WAR is not completely thorough. Realmuto is among the Marlins leadership. His effect on team morale, his relationship with the pitching staff as a catcher, advice he gives to other hitters and even his game-calling aren’t taken into account.

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I still recommend using this statistic, but proceed with caution. Other sports don’t have the luxury of an all-inclusive statistic that can compile almost every aspect of the game and present it directly as wins. WAR is a good starting point for a conversation on MVP, a player’s contract, or even a Hall of Fame vote. It can be used as a predictive tool for teams and fans to try and determine what the future holds.

But consider that baseball is not an automatic numbers machine. There are a lot of human factors like leadership, player development, injuries, and mental health that contribute to the results.

Thank you for reading, until next time.