WAR, what is it good for?

The hit 70's song would suggest that war is good for absolutely nothing, but in the modern baseball world, WAR can be very useful.  In baseball terms, Wins Above Replacement is used to value how much a player is worth compared to a replacement level player (a fringe major leaguer or bench player). 

WAR is used by the sabermetric community to summarize a player's impact in all aspects of the game.  For offensive players, the statistic incorporates hitting, baserunning and defense.  Pitchers calculate WAR based on a different set of advanced statistics relevant to their position.

During last season's MVP race, WAR found itself caught in the middle of a heated debate between the old school analysts and modern stat geeks.  The old school crowd was enamored by Miguel Cabrera becoming the first Triple Crown winner since Yaz in '67, while the stat geeks pointed out Mike Trout's superior impact in other aspects of the game. 

Now that Spring Training is in full swing, the debate has heated up once again. 

The case for WAR

There is no such thing as a perfect statistic that captures a player's full value, but WAR comes as close as anything we currently have.  Batting Average, Home Runs and RBIs are nice, but most of us have come to realize in recent years that there are far better ways to measure a player's value.  The RBI in particular is becoming a relic of the past, seen as an overrated statistic that is too dependant on a player's teammates.  After all, you can't knock in multiple runs with one swing of the bat if your teammates aren't getting on base in front of you.  While there is value to being able to drive in runs, the stat often gets overrated due to it's dependence on factors outside of the hitter's control. 

WAR is calculated with more accurate statistics, such as wRAA - Weighted Runs Above Average.  This stat measures the number of runs a player contributes to their team compared to the average player and is the primary factor in calculating the portion of WAR that relates to what takes place inside the batters box. 

When we compare the league's best players we tend to focus mainly on hitting stats, which often inflates the value in our minds of slugging home run hitters.  What this fails to realize is that other aspects of the game, such as baserunning and defense, are just as important.  WAR doesn't forget to leave those out.  What good is it to drive in runs at the plate if the player happens to be such a butcher with his glove that he gives up just as many runs in the field?  In terms of winning the game, saving runs on defense is just as valuable as creating runs on offense.  Casual observers will favor a hitter that puts up big numbers over a slick fielder because it's easier to justify that opinion with simplistic number such as HRs and RBIs, while advanced defensive metrics are too complex for most to pay much attention to.  In reality, these advanced stats may show that slick fielder actually provides more value to his team.

Let's not forget the value of baserunning either.  Those that favor sluggers that can belt extra base hits fail to realize that there's essentially no difference between a double and a stolen base that follows a single or walk.  A speedster on the base paths can be a distraction to the opposing pitcher, who is always worried about them swiping that extra base.  That can impact how the pitcher approaches the hitter at bat and become an advantage for the offense.  A good baserunner is also capable of taking an extra base when a teammate gets a hit, scoring from second or moving from first to third.  Not to mention that speed can also help a player leg out an infield hit or stay out of a double play.  These are factors that go into winning that often go overlooked.

The other benefit of WAR is that it takes into context factors such as league and park effects.  This allows the statistic to be used to compare players that have competed in other environments or even other eras.  The statistic also gives positional value, so a great defensive center fielder has more value to his team than a great first baseman.

The case against WAR

The main gripe people have with WAR is that nobody seems to agree on how to calculate it.  For one thing, the formula is too complex for the casual fan to pay much attention to, so if they don't understand where the statistic comes from then it's hard for them to find value in it.  There are also different variations of WAR.  Fangraphs and Baseball-Reference are the most common sources for WAR, but each uses a slightly different calculation for it.

Fangraphs WAR (fWAR) calculates WAR for pitchers using FIP, which is an advanced statistic that measure's a pitcher's ERA independent of fielding.  It's measured based on strikeouts, walks and HRs, while ignoring factors that are out of the pitcher's control, such as when the ball is put in play and the pitcher is forced to rely on his defense to create an out.  Baseball-Reference (rWAR) uses a different method by taking a pitcher's runs allowed and adjusting it to their opponents, team defense, park and role.  While top pitchers will still be rated favorably by either method, the differences in calculations can lead to different results and cause discrepancies in valuing pitchers.

The two methods also calculate defense differently.  fWAR uses UZR (Ultimate Zone Rating), while rWAR uses Total Zone.  Which version of WAR you choose to use may depend on which defensive method you value more.  Keep in mind though that UZR has only been tracked since 2002, so fWAR may not be as useful in comparing players to those from the past.  There is also much debate about the accuracy of advanced defensive ratings.  While we've come a long way in establishing new defensive metrics, they are admittedly far from perfect and typically require large sample sizes to take much meaning from them.  That's why some players show such drastic changes in defensive ratings from year to year.

Baserunning is calculated for fWAR using Ultimate Base Running, while rWAR uses a similar system of linear weights. 

The end result is that a player's WAR will likely look different depending on which version you use.  Take Seattle's Brendan Ryan for example.  Not many would consider him an impact player based on the fact that he hit a pitiful .194 with very little power last season, but as one of the game's best defensive short stops, he still has value.  How much value would depend on which source you used for WAR.  According to fWAR he was worth 1.7 wins above replacement, but rWAR had him at 3.3 because their scale weighs defense more.  That gap is the difference between being a role player and a borderline All-Star!

 What is it good for?

Not everyone is going to be convinced that WAR is a useful statistic, but to ignore it completely would be ignorant because it clearly has a purpose.  The misconception that the old school thinkers who shun the stat have is that stat geeks rely solely on this statistic as the be all, end all in determining an MVP.  That's not the intention of WAR.  On the FanGraphs page that explains the statistic, they are clear to point out that you should use more than one stat to evaluate players, but WAR is a useful reference point because it measures all aspects of how a player can impact the game.

Personally, I'm a big fan of the stat.  I'm also in the group of those that thought that Mike Trout should have been the MVP last season, but Trout's superior WAR wasn't the only reason I believe that.  WAR just helps back up my reasoning for why he's a more valuable player than Cabrera - because his baserunning and defense is that much more superior that it overwhelming makes up for the slight edge Cabrara had on offense.

How else do we know that WAR can be useful?  Because Major League GM's think it is.  Maybe not every team relies on it, but the market for free agency uses WAR as a guideline for a player's worth, with every 1.0 point of WAR being worth approximately $5 million.  That's how they determine that a superstar player that averages around 5 WAR per season is deserving of a contract worth $20-25 million per year.  It's hardly a perfect formula, but it can be used as a rough guideline.

Baseball is a game of numbers, with endless number of ways to evaluate a player with different statistics.  Some are better than others and the industry is constantly coming up with new formulas to calculate value.  WAR may not be perfect, but it's the closest thing we have to a statistic that properly evaluates player values.  That certainly makes it good for absolutely something.