Some years back, the need to settle disputes, the desire to exert influence and the insuppressible advancement of ideological change led the baseball world to WAR.
In the time since, the Wins Above Replacement metric has managed to weave its way into casual conversation and everyday analysis.
If you are unfamiliar (or need a refresher), the concept behind WAR is this: If you formed a team of freely available Minor Leaguers (aka "replacement-level talent"), it wouldn't win many games. In fact, estimates used for WAR peg that number at 48 (roughly a .300 winning percentage). So if you took Player A from that club and replaced him with Free Agent X, and the club won 54 games, that means that Free Agent X is worth 6 WAR, since the team improved by 6 games with him on the roster.
Thanks to its inherent appeal as a distillation of various contributing factors into a single number, WAR has served as a sort of gateway drug for folks just setting foot into sabermetrics. Thanks to its application across eras, WAR has heightened the Hall of Fame discussion. And thanks to the embrace it has received over time from the writers and TV broadcasters covering MLB, WAR has become, for better or worse, an almost de facto decider in the comparison of position players for the annual Most Valuable Player Award votes.
• Trout could pass these legends in WAR this year
WAR's biggest impact, however, is the influence it wields in modern front offices. Because as much fun -- or frustration -- the stat might foment in our daily discussion, any utilization of it for the purpose of actual roster construction supersedes our small talk.

And to be clear, they're definitely using it. While WAR is far from the only factor guiding the decision-making process, it has become a big one.
Here are a few testimonials…
• Phillies general manager Matt Klentak: "WAR puts all players in baseball on the same scale. There are ways to further refine that, but if you're looking for a quick and dirty way to get an assessment of a player, that's the way to go."
• Twins chief baseball officer Derek Falvey: "Any time you can get an aggregate value, sum it up into one value, it's helpful. It gives you a baseline metric to talk about."
• Giants president of baseball operations Farhan Zaidi: "The main value, particularly on the position-player side, is to be able to capture all the contributions of the player and really do an apples-to-apples comparison. So you're not saying, 'This guy is a plus hitter, but he's below average on the bases and in the field.' We can just say he's a two Wins Above Replacement player, taking all that into account."
• A's general manager David Forst: "What it does is allow you to work up from the bottom of your roster. Particularly with us, we're not going to have the top, top elite talent a lot of times in the free-agent market, but it does allow us to work up from the bottom and make sure that we're not falling behind with guys 20 through 25 on our roster."
You can protest WAR, and many have. Complex thinkers have derided it as too simple, and simple thinkers have derided it as too complex.
At this point, though, every team in baseball is employing some sort of WAR calculation. WAR is even, in all likelihood, a contributor to the slow-moving free-agent markets we've witnessed the last two winters. Because if teams have a statistical model telling them a player can reasonably be counted on for X contribution to the season win total, they're likely not going to bid much beyond the dollar value they place on X. And a more intuitive understanding of how to calculate a player's expected regression makes teams more cautious in handing out long-term deals (so far this winter, only one contract has exceeded four years, and that's Patrick Corbin's six-year pact with the Nationals).
"I think, more and more," Blue Jays president and CEO Mark Shapiro said, "organizations are starting to value on similar criteria, or at least in a similar way."
But just as there is no clear and established formula for the WAR data that fans and analysts have access to, the teams all have their own proprietary means of determining a player's value. In the public sphere, there are three sources for WAR -- Baseball Reference (bWAR), FanGraphs (fWAR) and Baseball Prospectus (WARP) -- and each has dozens of implementation details (you can compare them here).
It's the same in front offices. The Phillies' WAR metric (they call it "pWAR"), for instance, has different inputs than the calculation churned out by the division-rival Nats' statistical database (it's called "Pentagon," and Washington general manager Mike Rizzo joked that he hopes it's as secure as the real Pentagon).
"I've worked for a number of different clubs," Brewers president of baseball operations David Stearns said, "and I know first hand that -- even those clubs who, maybe from the outside, people think may view players very similarly -- they value them very differently. It's market-specific. It's which information clubs emphasize over others. You have to cater how you're valuing players to your specific situation, and that, by its very self, causes us all to look at players slightly different."
Added Falvey: "I think we all have different views of what we're shooting for. On some teams, maybe they're shooting for a higher floor or a system that gives credit for higher upside. A team with a higher payroll might keep the lottery tickets, because they can always buy a floor. But if you have a smaller payroll, you've got to keep the floor up, to a certain degree."
You might not be surprised to learn that none of the execs we spoke to for this story were willing to divulge their specific WAR calculation (some didn't want to address the topic at all) or instances in which it pushed their club in a certain direction in a personnel move. The importance of a proprietary evaluation method is exceeded only by the importance of keeping that method secure.
"That's our competitive advantage, having and believing we have information or methods or systems that other clubs don't," Stearns said. "We also believe that any advantage we have or other clubs have is fleeting. I've seen that first-hand, where you think you're making a breakthrough and the industry catches up in literally six months or a year. This is a fast-moving industry. New information sources are coming all the time."
Information sources -- most notably Statcast™ -- can influence the WAR inputs or even the relative value of the metric itself.
"I think, in different sports, you go through phases of construction and deconstruction of different stats," Zaidi said. "You take basketball, and in their analytics revolution, the first step was to figure out how good a player was in totality. Then, as they started having motion capture technologies, it became less about how good a player is overall and how can they could assess the individual skills of a player. 'Can he drive into the paint, and what's that worth to us?' So now you're moving back toward the traditional way of scouting players. I think, with the Statcast™ data, you're seeing more of that where we're starting to evaluate the players on their skills again, more than their overall contributions."
Whereas the public WAR data involves only surface-level statistics, teams have the option of involving their in-house scouting grades, combining the objective with the subjective. The next great frontier might be the quantification of player makeup and medical data for utilization in the WAR inputs.
"I'm sure somebody's going to figure it out or has figured it out," D-backs GM Mike Hazen said.
If or when they do, they'll keep that data away from the prying eyes of others. Because while WAR has its imperfections -- chief among them a regrettable acronym that inevitably leads to corny conflict references and Edwin Starr acknowledgments -- its importance in the modern game is undeniable.
"Information is the new arms race in baseball," Klentak said. "What types of components teams are able to feed into their calculations is ever-evolving, and it's competitive. If one team is ahead of the curve in a certain area, that might produce a slightly more nuanced WAR definition than what someone else might have."
And that's what every team is chasing. An evaluative advantage in a sport that has become a (wait for it) … WAR zone.