Wins Above Replacement (WAR): perhaps the most controversial advanced metric because a good number of writers and commentators have decided to use it as the be-all, end-all baseball statistic. It is designed to be a single number that represents how many additional wins a player’s team could expect to gain from that player’s presence as opposed to a “replacement” player from the minor leagues. A player whose statistics yield 5 “wins” above replacement would typically be considered an All-Star and a player with a WAR of 8 or higher would be an MVP candidate. It’s a statistic that’s easy to understand in terms of its meaning but difficult to comprehend in terms of how it’s calculated. Think of it as the “passer rating” stat of Major League Baseball. For decades, we’ve been told about a quarterback’s passer rating without understanding the math behind it. We just know its important and trust it.

One key thing to understand about WAR is that it is a counting stat, not a rate stat. The more years you play, the higher your WAR is likely to be. This is different than stats like Batting Average and ERA where a player can start going downhill in the later years of their career. WAR is, however, a counting stat in which you can count backwards. Some players, still on the field late in their career due to reputation, are actually playing at such an inferior level that their WAR is below zero. Hall of Fame pitcher Steve Carlton is a great example of this. In his final three seasons (ages 41-43), Lefty bounced around five different teams, compiling a 5.72 ERA and a -3.2 WAR. Still, in most cases, you’re going to have a higher WAR just by playing longer.

The one great benefit of WAR is that is the one and only statistic in which you can actually compare position players to pitchers. Needless to say, the way that its calculated for batters and pitchers is entirely different.

WAR for Pitchersas impossible as WAR for position players is to calculate for a lay-person, WAR for pitchers is even more complex because you can’t just add up the differing components. Let’s briefly go through some of the components that go into a pitchers’ WAR. The full NASA-level of details can be linked here on Baseball Reference.

  • RA9: simply the runs allowed by the pitcher for every nine innings. This is the same as ERA except that unearned runs are also counted. As we’ll, the quality of a pitcher’s team defense behind him is taken into account elsewhere.
  • RA9opp: the average number of runs scored by a pitcher’s opposing team, per 9 innings. Not all opponents are created equal. For a single year, one pitcher might get the luck of the draw, toeing the rubber against the worst hitting teams while another might draw the short straw with juggernaut offensive teams. These things tend to ever out in the long term but not always. A recent example is to compare Mike Mussina, who spent his entire career in the rugged A.L. East and Tom Glavine, who pitched exclusively in the less offensively prolific N.L. East. Glavine’s career RA9def was 4.54, Mussina’s was 4.94. That’s a difference of 0.4, just under one full half a run per 9 innings. With numbers we understand, Mussina’s 3.68 career ERA is thus more impressive than Glavine’s 3.54 (and this is reflected in their respective numbers for ERA+. Mussina’s (123) is higher than Glavine’s (118)
  • RA9def: runs per 9 innings of support (or lack thereof) from a player’s defense. This puts a pitcher’s performance in the context of the overall defensive numbers of his team. When you find a pitcher with a surprisingly high or low WAR, this is the first place to look to see why.
  • RA9role: gives more credit to being a starting pitcher than a relief pitcher.
  • PPFp: adjusts for the ballparks in which a pitcher threw. Unlike a position player, whose road starts will typically be split around the league, a pitcher might, by luck of the draw, have a disproportionate number of starts in pitcher-friendly or unfriendly starts.

One thing that trips people up sometimes with pitchers is that they have two aspects of the game that contribute to their WAR. The biggest component by far is how they perform on the mound. However, in today’s National League, in interleague games in N.L. and in all of baseball before 1973, pitchers also have had to swing the bat.

Hall of Fame pitcher Red Ruffing had a career pitching WAR of 55.4, which is on the low end of starting pitchers enshrined in Cooperstown, although certainly not the lowest. His career ERA of 3.80, on the other hand, is the highest for any inducted pitcher. Ruffing, a member of six World Champion team with the Yankees, also was a decent hitter and was used as a pinch-hitter over 250 times. In his career, he hit .269 with 36 home runs and 273 RBI for a rate of 7 HR and 50 RBI for every 162 games. Due to the positional adjustment (the value of being a good-hitting pitcher), Ruffing’s career batting WAR was 15.0. That would put his overall WAR at 70.4, which theoretically would move him from a questionable Hall of Famer to an indisputable one.

An amazing thing to contemplate: because of the value of being a pitcher, Ruffing’s batting WAR is higher than that of the Philadelphia Phillies’ Ryan Howard (14.9 WAR), who hit 382 major league home runs. It’s also higher than Bill Buckner’s lifetime WAR (14.8), despite his 2,715 career hits.

NOTE for this site: when showing lists of pitchers and their WAR, we’re focusing solely on their WAR as pitchers. In the vast majority of cases, the hitting value that a pitcher adds is functionally irrelevant to whether they deserve a Hall of Fame plaque or not.