Stat of the Week: Wins Above Replacement (WAR)

Clip art illustration of a Cartoon Tiger with a Missing Tooth

Let’s get this out of the way early because it’s going to come up in a couple weeks when SABR Toothed Tigers New English D hands out a very controversial MVP award to someone not named Miguel Cabrera.

This week’s Stat of the Week is Wins Above Replacement (WAR). It’s been in the news a bit lately, so let’s all get on the same page about it.

First, there is something you should know. There are two different WAR. One belongs to Baseball Reference, one belongs to Fangraphs. They are different primarily because they use different measures of defense (more on this later). I will always cite Fangraphs on this site, but only for the reason that I like how they present their data.

The concept behind WAR is the same for both sites. How many wins does a given player add to his team above what a replacement level player would? A replacement level player is defined as a widely available AAA type player. Think Mike Hessman, Jeff Larish types if you followed Tigers minor leaguers in the last decade.

This is a pretty simple idea. What is the difference in wins between Prince Fielder at 1B versus Jeff Larish at 1B if everything else were equal? That is WAR in the abstract.

More concretely, a team that only played replacement level players would win about 50 games per season. As we’ve mentioned a lot here, even terrible teams win sometimes.

So what does WAR look like? For position players, you want to post at least a 2.0 WAR in a season to be considered a “starter.” Below that and you’re a backup or a minor leaguer. 2.0-4.0 WAR is considered solid, 4.0-6.0 is pushing All-Star to superstar levels, and 6.0+ is MVP type guys. You can roughly use the same scale for starting pitchers. Relievers are much different because they play so much less. Better than 1.0 WAR for a reliever is good, 2.0 is great, and 3.0 is excellent.

Let’s talk theory first. The common retort to this is that “Miguel Cabrera has to be worth more than seven wins to the Tigers! If you took him out, they’d suck!”

This isn’t really accurate. Think about it. The Tigers won 88 games, Cabrera posted a 7.1 WAR. Let’s round up to 8.0 WAR to be generous as that difference is attributed to what WAR considers poor defense (more on this later). If the Tigers did not have Cabrera and replaced him with a minor league player ala Ryan Strieby, the Tigers would go 80-82 according to WAR theory. That’s actually pretty realistic if you just look at it. That’s 9% of their wins concentrated in 4% of their roster.

80-82 isn’t very good, but it’s not horrible. After all, they Tigers have a good team around him. Let’s take away Verlander’s 6.8 WAR (rounding up to 7) and we’re at 73-89. Good for fourth worst in the AL. Essentially, if we take Verlander and Cabrera off the Tigers according to WAR, they would only be better than Cleveland, Minnesota, and Boston in 2012.

You have to buy that. They still have Fister, Scherzer, Sanchez, Fielder, Jackson, etc. They would be much worse, but still not a minor league team. Take away Fielder’s 4.9 WAR and we’re down to 68-94. Only the Twins were worse. That sounds about right when you really think about it.

So that’s the theory, but what about the practice. How do we calculate WAR? What WAR seeks to do is combine hitting, baserunning, and defense into a single number calibrated to the only thing we actually care about, wins. Each action earns a “run value” based on how often that action contributes to run scoring and the accumulation of 10 runs is about equal to 1 win.

WAR takes into account how much better than average a player is offensively using wOBA and coverts it into an overall run value, wRAA, based on the number of plate appearances a player has had. You take that wRAA and divide it by the Run to Win value of that year (usually about 9 to 10). That gives you offensive WAR. Baserunning has a similar type formula based on how many bases you take and how many you steal. Defense is based on UZR for FanGraphs and DRS for Baseball-Reference, which all come out in run values converted into wins in the same way. Overall WAR is also adjusted for the position you play.

For pitchers, FanGraphs uses Fielding Independent Pitching (FIP) and includes the number of innings pitched, park effect, and similar adjustments and Baseball Reference uses runs allowed and controls for the quality of your defense.

Simply put, WAR is trying to measure the total contribution a player makes with his play on the field. It obviously doesn’t measure things like leadership that reflect on other players (or moving to a new position!), but everything they do on the field is captured. Surely no one can challenge this concept.

WAR takes various statistics and combines them and scales them to churn out a number. The math is based on baseball history and what has been shown contributes to winning. For example, WAR values OBP over AVG because walks are important, but missing from average. It doesn’t care so much about RBIs because you can’t drive in runs if no one gets on base ahead of you. The math behind this, which I won’t subject you to any more unless you really want me to (here’s Fangraph’s page on WAR), is rooted in the game’s history and they adjust it every year to pick up new information, but it’s always scaled to that year’s replacement level so you can compare across eras.

WAR is not a perfect, exact measure of a player’s value, but it is a good one if you sum a team’s WAR and compare it to their actual win total + 50 (again this number has been slightly adjusted). It’s not a be all end all. If a player is 4.6 WAR and another is 4.5 WAR, they are essentially equal. There is margin of error. But WAR does give you a good sense of how much this player helps his team win with his own performance.

The argument against WAR is twofold. First, it’s complicated. It turns out a pretty good number, but it’s hard to grasp. You can’t watch a game and immediately see how Player X’s WAR is impacted like you can with HRs or average or walks. It’s not a stat, it’s a metric. It weighs the value of each action based on how those actions normally lead to wins for your team. So it’s hard to follow. You have to look at the numbers, you can’t figure them out and follow them as well. I’m not arguing we throw the others out in favor of WAR, but when you want to compare players who player different positions and on different teams, WAR equalizes that through a positional adjustment and other devices.

The other problem with WAR is defense. Defense is really hard to measure. Fielding percentage is not a good measure because that only tells me how often you make errors, it doesn’t tell me what kind of errors. It doesn’t tell me about your range.

WAR uses UZR (Ultimate Zone Rating) or DRS (Defensive Runs Saved) to measure defense. They are both metrics based on range and execution, with human viewers judging every play based on if it should be made routinely and how much harder or easier a play is from average difficulty. So there’s some subjectivity, but it’s much better than any of the traditional numbers. Plenty of people criticize these numbers because they fluctuate a lot and give some weird results on occasion.

Essentially, defense is WAR’s weak leg, but it’s getting better and is much better than anything traditional. But this means we can’t use WAR as a final word. We have to look at other things and use our eyes.

Don’t run from WAR because it is complex math. You can check it yourself by seeing what it turns out in a given year compare to a team’s actual results. The Tigers position player WAR and pitcher WAR sums to 43.9 this season. 50 + 43.9 = 93.9 which misses the Tigers win total by a whopping 6%. Not bad. It works even better with bigger samples.

Question WAR because it may be imperfect. It’s not trying to boil baseball down to a spreadsheet, it’s trying to correctly value on field actions. Having more RBI doesn’t make you a better player than someone else. Hitting more homeruns doesn’t either. If no one gets on base for you, you can’t drive them in. If you play in San Diego instead of Cincinnati, you’ll hit fewer bombs.

WAR is an equalizer. It allows us to compare individuals playing a team game. It’s a good thing. Don’t take it as doctrine, take it as information. The concept is great, the execution is pretty good and getting better. What WAR does is trying to measure value accurately, rather than based on old statistics that were invented before we had a good idea about what mattered in baseball. Check out our Stat Primer page to learn all about what stats are good and which aren’t so good.

And here’s a WAR calculator. Learn how to use it here.

53 responses

  1. […] turn of events, however, it was not Chris Davis who won New English D’s “Race to 1.0 WAR,” but rather the A’s shortstop, Jed Lowrie. Mr. Lowrie has 30 plate appearances in his […]

  2. […] two weeks. In 12 games, Upton has 7 HR, a .348/.415/.891 slash line, and a 242 wRC+, good for 1.1 WAR. Fielder only has 4 HR, but his .429/.527/.833 line and 250 wRC+ are no less impressive alongside […]

  3. […] eventually stop referring to sample size, but one particular player who is near the top of the WAR leaderboard caught my eye; Brandon Crawford. The Giants shortstop is known for his glove, but his […]

  4. […] face it, it’s pretty much the same thing. Second, I’ve determined these ranks by Wins Above Replacement (WAR) because it’s the easiest way to boil players down to one number who play different positions […]

  5. […] in Tigers history. Today, I though I’d give you a ranking of the best Tigers teams ever by Wins Above Replacement (WAR), which will allow for a comparison between […]

  6. […] give you the worst Tigers teams ever. The methodology is the same. I’m ranking the teams by Wins Above Replacement (WAR), not because that’s the best way, but because it’s easy to take a look at win totals […]

  7. […] fewer wins than the 2003 Tigers and currently have the league’s worst offensive by wRC+ and WAR and the 6th worst pitching staff by WAR. As a team they are hitting .221/.281/.316. That line […]

  8. […] the month of May. On the bump, the Tigers are far and away the best staff in baseball with a 13.4 WAR overall thanks to a 6.5 WAR month of May in which they struck out 9.9 batters per 9 and walked just […]

  9. […] If you’re looking to catch up on sabermetrics, check out New English D’s posts on FIP, WAR, wOBA, wRC+, and […]

  10. […] his career. He has the lowest ERA, FIP, and xFIP of his career. He’s on pace for his highest WAR and might get there by August. He’s added a curveball and is using it along side his changeup […]

  11. […] 2-1, 30 IP, 9.68 K/9, 1.76 BB/9, 2.93 ERA, 2.77 FIP, 2.14 xFIP, 0.8 WAR. […]

  12. […] allows inherited runners to score. xFIP isn’t available for all of the years in question and WAR is a counting stat, so it would be misleading when comparing pitchers who threw a considerably […]

  13. […] is the offensive component of Wins Above Replacement (WAR) and is based on wOBA and is rather simple to calculate if you have all of the necessary […]

  14. […] On this edition of New English D Audio I discuss how the Tigers should handle the bullpen and Jose Valverde, Nick Castellanos’ breakout at Triple A, and how we should value Jhonny Peralta given his big offensive season and somewhat controversial defense. The conversation features material regarding how one can invent a closer, the great season of Darin Downs, Nick Castellanos’ big season, and various statistics surround offensive value such as wRC+, wRAA, and wOBA in addition to WAR. […]

  15. […] Seasons of the Last Decade. The rules are simple. These are the players who posted the highest Wins Above Replacement (WAR) values while having a slugging percentage that was below league average from […]

  16. […] adding to his brilliant season and Cy Young campaign. Scherzer now leads all AL pitchers in Wins Above Replacement (WAR) with 3.3 (also in Run Support per 9 with 7.83). I mean, check this out. He threw almost nothing off […]

  17. […] but try to think of these as the state of the position at the halfway mark. I’ll be using Wins Above Replacement (WAR) to generate the rankings because it is the number that best captures the entire value of a player. […]

  18. […] but something is incredibly interesting about Dirks this season. Last year, he was worth 1.6 WAR in 344 PA. This year he’s at 1.4 WAR in 244 PA. So he’s actually a little ahead of last […]

  19. […] a +5 DRS or +5 UZR is five runs better than league average at their position. 10 runs is equal to 1 Win Above Replacement (WAR). These are counting stats, so you accumulate them as the season goes on, although I believe they […]

  20. […] Probability Added (WPA) is a typical way to fix this, but this feels too context dependent for me. WAR is always a nice combination of these kinds of measures, but WAR is a counting stat so how much a […]

  21. […] rules are simple, these are The Nine best season by Wins Above Replacement (WAR) for qualifying starting pitchers who won fewer than nine games. In MLB history, there are 8286 […]

  22. […] (71 wRC+) and despite a reasonably good defense (11.3 UZR), the 24th ranked pitching staff (5.1 WAR) isn’t enough to keep them out of the cellar. By WAR, they rank 29th in baseball with 6.5, […]

  23. […] up and down guy despite making it to the show so young. Then something funny happened. Here are his WAR numbers for […]

  24. […] more, but try to think of these as the state of the position at the halfway mark. I’ll be using Wins Above Replacement (WAR) to generate the rankings because it is the number that best captures the entire value of a player. […]

  25. […] curious fan with little guidance. It’s not hard to tell why some people here us talking about Wins Above Replacement and start thinking we’re nuts. It’s out job to explain what we’re doing and […]

  26. […] you’re someone who likes Wins Above Replacement (WAR) or Win Probability Added (WPA) it all points in Lee’s favor as […]

  27. […] that Miguel Cabrera is having an amazing season. He’s leading MLB in Wins Above Replacement (what is WAR?), wRC+ (what is wRC+), wOBA (what is wOBA?), batting average, on base percentage, and is 2nd in […]

  28. […] more, but try to think of these as the state of the position at the halfway mark. I’ll be using Wins Above Replacement (WAR) to generate the rankings because it is the number that best captures the entire value of a player. […]

  29. […] of the 2013 season the Detroit Tigers were baseball’s best pitching staff with 17.1 WAR (what’s WAR?), a 3.26 FIP (what’s FIP?), and a 3.35 xFIP (what’s xFIP?). In fact, their starting […]

  30. […] more, but try to think of these as the state of the position at the halfway mark. I’ll be using Wins Above Replacement (WAR) to generate the rankings because it is the number that best captures the entire value of a player. […]

  31. […] spent 15 of his 17 MLB season in Detroit and accumulated 54.2 WAR (what’s WAR?) in a Tigers’ uniform and 54.6 WAR overall. He was a very good player in every way. He was a […]

  32. […] said, despite a respectable 3.69 ERA, 3.35 FIP (what’s FIP?), and 3.0 WAR (what’s WAR?), there are some signs of trouble. He has the lowest K/9 and highest BB/9 since his 2008 […]

  33. […] he just isn’t having a great one. He’s been worth just 1.0 wins above replacement (what’s WAR?) in 101 games despite being worth close to 5 WAR in each of the last two seasons. The defensive and […]

  34. […] is Total Zone until 2002 and then UZR. This is what FanGraphs uses for the defensive component of Wins Above Replacement (WAR). What you see on the surface here is that Hunter is essentially an average defensive player over […]

  35. […] (what’s wRC+?) in July and were second in the AL in position player wins above replacement (what’s WAR?) The story of the month offensively was Victor Martinez’s resurgence as he posted a 180 wRC+ […]

  36. […] The idea is simple. I ranked the teams at the beginning of the season based on how well I thought they would perform over the entire year. I am doing the same thing here, but I just have new information to include based on what I’ve seen so far. Note that when discussing offensive rankings I will be using wRC+ (what’s wRC+?) and when discussing pitching rankings I will use wins above replacement (what’s WAR?). […]

  37. […] line which produced a 48 wRC+ (what’s wRC+?). In total, his career wins above replacement (what’s WAR?) was -1.1. That’s a small sample and you can’t make too much of it, but Tuiasosopo […]

  38. […] than average and all of the main five starters have at least 2.0 wins above replacement or more (what’s WAR?). In fact, despite having an ERA a bit worse than their FIP due to some less than perfect defense […]

  39. […] is clear. Peralta was having a great season, providing 126 wRC+ (what’s wRC+?) and 3.7 WAR (what’s WAR?), essentially functioning as the team’s second best everyday hitter overall. The Tigers have […]

  40. […] the best offense and best staff in baseball, good for the highest number of wins above replacement (what’s WAR?) of any club in the sport. As it stands, only the Pirates have fewer losses than the Tigers and […]

  41. […] on pace for something like a 3.5 WAR (what’s WAR?) season, which is very good, but it’s not quite like the  5.2 mark he posted a year ago. As […]

  42. […] season in his career by UZR (what’s UZR?), but is still already a half a win better by WAR (what’s WAR?) than his previous high despite there being 45 games left in the […]

  43. […] is an excellent starting pitcher despite a somewhat down season, posting an MLB best 31.9 WAR (what’s WAR?) since the start of 2009. In the same period, he has a 3.04 ERA and 3.00 FIP in 161 starts. Even if […]

  44. […] AL. Let’s start with the candidates. To do so, I’m going to use Wins Above Replacement (what’s WAR?) as a starting point. I’m going to look at WAR only to determine who should be in the […]

  45. […] has had a bit of an up and down career with the Tigers. He’s been worth 3.8 WAR (what’s WAR?) over his four seasons with the club which included 14 starts in 2011. He’s generally had a […]

  46. […] the second place A’s in wRC+ 124 to 116 (what’s wRC+?) and in Wins Above Replacement (what’s WAR?) 7.0 to 6.8 over the Red Sox. Cabrera posted an insane 212 wRC+ followed by Victor Martinez at 158. […]

  47. […] 69 innings, turned in a 2.22 ERA and 2.43 FIP (what’s FIP?) to go along with a 1.5 WAR (what’s WAR?). He has struck out 26% of opposing hitters and walked just 5.5%. He’s been otherworldly […]

  48. […] on how well he can play. Entering the suspension, Peralta had what is still the second highest WAR (what’s WAR?) on the team at 3.6. He hit .305/.361/.461. Among the full time guys, only Cabrera has a higher OBP […]

  49. […] Miguel Cabrera or Mike Trout great, but he does a lot of things well. He’s averaged 3.4 WAR (what’s WAR?) per 600 plate appearances and has been as high as 5.2 in a season and never lower than 2.4. He […]

  50. […] to use numbers that control for the era, so we’re going to start with Wins Above Replacement (what’s WAR?), but I’ll run through some other numbers as well. Second, wins are tied to some aspect of […]

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