What WAR Is Good For

On Friday, ESPN.com’s lead baseball story was title “Let’s Corral the WAR Horse,” and the image used in the rotation feature box was simply a white sign with the words “NO WAR” attached to a stick, presumably a stock image of a sign from an anti-violence protest. In the piece, Jim Caple — a writer I like, have spent a little bit of time with, and who is a pretty good advocate for logical thinking, by the way — explained why he’s a little frustrated with what he perceives as an over reliance on WAR as the stat’s popularity grows.

Quoting Caple:

So yes, I like WAR as a statistical measure. My issue is this: I don’t like the increasing over-use of (and over-reliance on) WAR as THE definitive evaluation of a player’s worth.

This was particularly true during the Mike TroutMiguel Cabrera MVP debate last fall. For instance, consider this headline on an ESPNLosAngeles.com story in late September: “Mike Trout Is Your MVP (WAR Says So).

That was just one of many stories focusing on WAR in the MVP race, where the stat became a big factor in analysis of the players, as Bleacher Report noted.

Now, Cabrera wound up winning the MVP by a wide margin, so WAR wasn’t a decisive factor in the award vote. (I voted for Trout, though I did not base my ballot on WAR.) But I just found it tiresome to keep reading all the references to it, as if WAR was the only stat that should be considered, and leading a league in batting average and home runs and RBIs — as Cabrera did in becoming the game’s first Triple Crown winner since 1967 — was somehow a mere accounting trick.

We saw it again during the recent debates over the Hall of Fame, when there were more mentions of the candidates’ WAR record than you’d find in a presidential campaign. How this might have affected the case for Jack Morris is one of the reasons the over-reliance on WAR drives me nuts.

I think Caple has a pretty decent point, to be honest. I wouldn’t necessarily criticize the usage of the statistic because of a headline designed to draw traffic or because of something that was written about on Bleacher Report, but we’ve probably all seen instances where WAR was used to end a discussion rather than promote one. Caple’s correct that WAR was never designed to be the only statistic that matters, nor should we view it as some kind of infallible truth. It is not a perfect metric; it contains some imperfect inputs and it does not sum up the entirety of baseball in a single number. If it did, baseball would be boring, and talking about the sport would be a lot less fun than it is now.

So, to an extent, I agree with Caple’s larger point, while not necessarily agreeing with all the points he made along the way. However, I think it’s worth talking about why WAR has become so ubiquitous over the past few years, and what its sudden rise in popularity should tell us about every kind of statistic. And I’ll start by leading off with Caple’s final two sentences:

We need to look at many stats to assess players, and one of them should be WAR. But it shouldn’t be the only stat we look at or cite.

To that last statement, I’ll respond with a question: what is the point of any useful statistic? To me, a good stat is simply the answer to a question that is commonly asked.

Whether it is batting average, strikeout rate, swing percentage, or average velocity, each one was designed to answer a pretty simple question. How often does that player get a hit? How often does he swing? How hard did that pitcher throw his fastball? These are questions that are worth asking, and so we track things in baseball that allow us to answer those questions with data, assuring us of getting a pretty accurate answer in most cases. In fact, I think a litmus test for the usefulness of a statistic can be simply translating the definition into a question and figuring out how often anyone ever asks that question?

Let’s take Wins for a pitcher, for instance. For a long time, they’ve been hailed as one of the most important statistics in baseball, but the actual question that statistic is answering goes something like this:

“How many times did that pitcher complete at least five innings, leave the game with his team having outscored the opponents through the point at which he was removed, and then watch his relievers finish the game for him without surrendering the lead that his teammates helped create in the first place?”

No one would ever ask that question. It’s not something that’s worth knowing, nor does it help anyone understand what actually happened in any real way. And that’s one of the reasons why W-L record for a pitcher has been marginalized and will eventually just be discarded, since it serves no real purpose. It answers a useless question, making it mostly a useless statistic.

We care about stats that answer questions that we care about. And there is perhaps no question in baseball that is asked more frequently than “how good is that player?” Whether it’s at the bar talking with your neighbor or discussing a blockbuster trade at the winter meetings, the question of a player’s overall worth is everywhere. And, at its heart, this is the question that WAR seeks to answer.

No other statistic in baseball attempts to answer that question. For a hitter, the commonly quoted statistics are things like at-bats (how much did he play?), batting average (how often did that guy get a base hit?), on base percentage (how often did he reach safely?), slugging percentage (how much power did he hit for?), and of course all the various counting stats that simply add up how many times a specific thing happened, such as singles, doubles, home runs, stolen bases, errors, etc… For a pitcher, it’s basically the same thing, with innings pitched serving as the answer to how much a guy pitched, with things like ERA and FIP serving as the measures of pitcher quality, despite the fact that they’re answering questions that are much more narrow.

If someone who didn’t know anything about baseball came up to you and asked you who the best player in baseball was right now, your answer would probably be someone from the group of Mike Trout, Miguel Cabrera, Buster Posey, Ryan Braun, Robinson Cano, Joey Votto, or Justin Verlander. But, what would you tell them if they then asked why?

Well, Miguel Cabrera has the highest batting average of any qualified player over the last three years, but that doesn’t answer the question of why he’s a better hitter than Joey Votto, who is number one in on base percentage. And how would you even begin to explain why Cano’s slugging percentage relative to other second baseman is more impressive than Verlander’s ERA? It’s not just apples and oranges anymore; now we’re mixing in things like sriracha, oreos, and Copper River Salmon, and it’s becoming a question of individual preference.

At that point, when the conversation is just beginning, something like WAR is exactly what you need, because it attempts to answer the very basic question that is being asked: “Is this guy better than that guy?” Even complicated calculations like wRC+ or xFIP- don’t attempt to answer that question; they are simply more technically correct ways of answering others questions that get at valuing a specific set of skills.

There are thousands of baseball statistics. Most of them are narrow, precise instruments that provide a single answer to a simple question. Pretty much all of them are incapable of answering the single most asked question in baseball, which is why an all-encompassing metric like WAR has risen to prominence in the first place. There are simply times when someone asks a general, imprecise question about the value of a certain player, and WAR is the perfect tool to provide a general imprecise answer to that question.

“How good was Mike Trout last year?
“Well, according to WAR, he just had the best age-20 season in baseball history.”
“So, pretty great, then? Okay, thanks!”

Was it actually the best age-20 season in baseball? To answer that query, you’d need to look at other measures and get a more narrow view of his season relative to the other great 20-year-olds who have performed at incredible levels. WAR usually isn’t precise enough to make those kinds of separations, and it isn’t the right tool to try and dissect small differences. However, now matter how many different measures you look at, at the end of the day, you’re usually going to have to figure out how to add those back up to answer the original basic question, and you need to know how valuable certain aspects are relative to others.

When it comes to deciding whether Jack Morris belongs in the Hall of Fame, we should absolutely look at the whole picture, and not just end the discussion with a simple recitation of his career WAR total. After all, Morris +56.9 WAR is nearly a dead on tie for Sandy Koufax’s +57.3 WAR, and no one’s trying to get Koufax evicted from Cooperstown. Even the staunchest defender of advanced metrics would agree with the notion that a player’s Hall of Fame case deserves more consideration than simply looking at a player’s WAR and calling it a day. WAR should almost never be the end of the conversation, unless that conversation starts with “Would you vote for Willie Bloomquist for the Hall of Fame?”

However, WAR is a great place to start that conversation. It is a fantastic filter, grouping players into manageable sizes of comparable performances, allowing for further evaluation of those who are candidates for the answer, depending on what the question is. It is not precise enough that anyone should be declaring a definitive answer based on a decimal point difference. Just like every other statistic in baseball, a one year result does not equal a player’s true talent level, so don’t claim that WAR thinks that Chase Headley is a better player than Miguel Cabrera. Depending on what question you’re asking, you may very well want to give less weight to a player’s defensive rating.

WAR is not the be-all, end-all of baseball statistics. However, it serves a great function as a good answer to a commonly asked question, and at the end of the day, that is really the entire point of a statistic. There are times when one wants to do a deep dive into every aspect of a player’s overall game, and WAR is not the right tool for that job. But, as a quick summary of a player’s overall value, it is the best tool for the job.

Sometimes, a big wide hammer is exactly what you need, and having access to 10,000 scissors isn’t helpful at all. You should absolutely have both a hammer and scissors in your tool belt, but don’t be surprised if you use the hammer more often, especially if the job is simply to pound a bunch of nails.

Dave is the Managing Editor of FanGraphs.

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Matt Huntermember
11 years ago

I think you ended that quotation a little early, Dave.

Pat G
11 years ago
Reply to  Matt Hunter

I read Caple’s piece on friday, and the quote should end after the paragraph that starts with “We saw it again during the recent….” (for anyone who is confused)

Carson Cistullimember
11 years ago
Reply to  Matt Hunter

Fixed. HTML was trying to sabotage Cameron!