Image Credit: Fangraphs
Wins Above Replacement (WAR) is a cumulative, all-in-one baseball statistic that assigns each player a score based on his contributions as a hitter, baserunner, fielder, or a pitcher, above a replacement level player. WAR is an important stat to understand, primarily because it highlights many of the otherwise undervalued aspects of player evaluation. Sean Smith of BaseballProjection.com developed the statistic.
A replacement level player is held constant across all organizations, and is the caliber of a career minor leaguer, or “AAAA” player (think Paul Janish, Austin Romine, or Josh Rutledge). A team full of replacement level players will have a winning percentage of .294, or go 48-114, three games below the 2013 Houston Astros.
Scores can range from below zero to as high as 10+. Babe Ruth holds the single season WAR record, a 14.1 mark set in 1923, his MVP season. Typically, anything less than 0 is below replacement level, meaning the manager should sit that player and call up the next guy to take his place (think Ubaldo Jimenez, Carl Crawford, or Pablo Sandoval). Anything between 0 and 2 is the caliber of a backup player (think Danny Espinosa, Ryan Hanigan, or Kevin Gausman). Anything above 2 is a starter (think Didi Gregorius. Matt Wieters, or Jordan Zimmermann). Anything above 5 is All-Star caliber (think Manny Machado, Mookie Betts, or Max Scherzer). Anything above 8 is an MVP candidate (think Bryce Harper, Mike Trout, or Clayton Kershaw).
WAR serves many purposes, including deciding which player deserves consideration for the annual MVP, Cy Young, and Rookie of the Year awards, as well as who is worthy of induction into the Hall of Fame. WAR can be used to compare players across teams, leagues, and generations. It is used by front offices across Major League Baseball every year. It is arguably the most useful statistic; the closest statisticians have come to getting it all down to one number.
Some of what WAR tells us is obvious. WAR tells us that Bryce Harper was the best player in baseball last year, the Red Sox have the best offense in baseball thus far this year, or that Babe Ruth is the greatest player of all time. But some of what WAR tells us is not so obvious yet just as useful, giving those who understand the statistic a competitive advantage.
If the season ended today, who would be the American League MVP? You may take a look at David Ortiz’s numbers and pick him in a heartbeat. He leads by a landslide in several major statistical categories, including ones that we will cover on subsequent Sundays. He is on pace to set the single season record for doubles. He is carrying the prolific Red Sox offense and keeping the team afloat amidst an absence of starting pitching. Going by hitting alone, David Ortiz is your MVP.
However, Big Papi can only hit. That is just one aspect of the game. Defense and baserunning are also important, and Ortiz suffers in those categories. David Ortiz is a station-to-station baserunner. He will rarely advance multiple bases on a single, if ever. And he does not play defense.
Designated hitters, all else held constant, are the least valuable players. A shortstop is involved in so many plays and has lots of ground to cover. A good defensive shortstop can be crucial in run-saving, and therefore, winning. Positions such as pitcher, catcher, shortstop, third base, second base, and centerfield all receive adjustment bonuses, given the difficulty of those positions and the lower supply of capable players there. Positions such as first base, left field, right field, and designated hitter receive adjustment penalties, as those positions are comparably easier to man.
If the season ended today, the AL MVP ought to be Ortiz’s teammate, Xander Bogaerts, not as good a hitter as Ortiz but a much more valuable player in the aggregate. Bogaerts runs better, fields better, and plays a more important position. Bogaerts on the whole is worth more runs, and therefore wins, to a team.
Last season, Mike Trout led the American League in WAR for a fourth consecutive season (9.4). Trout has only been MVP once (2014), but it can be argued he should have four MVPs already instead of one MVP and three runner up finishes (2012, 2013, and 2015). Josh Donaldson (8.8) took home the MVP award last season but finished second in WAR. The third-highest WAR in the American League last year was Kevin Kiermaier (7.3), who finished only 17th in the MVP voting. The example of Kiermaier illustrates the importance of defense to a team’s ability to win. Kiermaier saved 42 runs in the Rays outfield last season, by far the most in baseball by a single player, good for an AL Platinum Glove (To put that in perspective, Manny Machado saved 35 runs at third base in 2013, his AL Platinum Glove season.). Kiermaier's defense was so superb it enabled him to finish in the top three for Wins Above Replacement despite contributing below average hitting.
Previous "Sunday Morning Sabermetrics" articles:
Pythagorean W-L (June 5th): http://bigtrain.org/news/?article_id=340
Slash Line (June 19th): Rise and shine this Father's Day with the Slash Line, that is, the expansion of batting average that includes On Base Percentage (OBP), Slugging Percentage (SLG), On Base plus Slugging (OPS), and Adjusted On Base plus Slugging (OPS+).