What is WAR? An explainer on one of baseball's advanced metrics: Wins Above Replacement

The baseball world has undergone a revolution, one that has taken place over the past few decades. It has transformed how many view the game. And although no metric can completely quantify the game as a whole, those in and around baseball now have better ways to break down what's happening and what might happen next.

In addition to batting average, RBIs, pitcher wins and ERA, some advanced metrics — fWAR, wRC+, BABIP, FIP, OOA, wOBA and so many others — give us a more complete picture of what's going on or why something happened. It isn't just to replace the "eye test" or scouting, but it is to be layered on top of everything else, sort of like a blue print.

And why is it so important for these metrics to appear in our coverage, in addition to being able to tell more of the story and in more accurate ways?

That's simple: because teams are using advanced metrics as a part of their decision making, whether it comes to player evaluation as a whole, free agency, trade decisions or the draft. Anything and everything. And since teams have rolled analytical ways of evaluating players into their decision-making, it is imperative that the coverage of those teams reflect that.

Otherwise, readers and listeners are being left out on key aspects that evaluate how teams are operating in this modern age of baseball. Pitcher wins and RBIs leave a lot of context on the table if they are being used to evaluate players against one another.

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Some readers have sent emails asking for explanations of some of these advanced numbers, so we thought we'd offer some explainers to give extra context. And in the future, whenever these metrics are used in stories, these explainers will be linked and readily available for a refresher.

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Up first: WAR.

What is Wins Above Replacement (WAR)?

Wins Above Replacement aims to measure a player's value to his team in all facets of the game by citing how many additional wins he'd be worth over a replacement-level player, meaning a minor league or readily available free agent fill-in.

So if a player has 4.5 wins in a given season, that means he was worth an extra 4.5 wins to his team over what a replacement-level player would done production-wise. An All-Star caliber player tends to be around, at least, 3-6 WAR in a given season. Once you get over 6 WAR for a single season, and especially once 7 or 8 WAR are eclipsed, you're probably talking about an MVP candidate.

For position players, batting, base-running and fielding are all components. It is then adjusted for position and league trends that year, making it easier to compare a particular second baseman's value in 2022 with a specific left fielder in 2016. Pitchers also have their calculations adjusted for league trends and ballpark factors.

Different sources do have different calculations. When you see "fWAR" that is referencing FanGraphs' formula, while "bWAR" is Baseball-Reference and WARP (Wins Above Replacement Player) is used by Baseball Prospectus. FanGraphs' formula — fWAR — is mostly used in our coverage.

As it relates to the Guardians, last year can be analyzed.

Jose Ramirez (36 home runs, 103 RBIs, 27 stolen bases, above-average fielding rating) was worth 6.5 fWAR, again near the top of the league. (He's already accrued 3.8 fWAR in 59 games this season.) Amed Rosario, after his torrid second half, came in a 2.4 fWAR — a positive contributor. On the other side, Jake Bauers, who struggled in Cleveland and couldn't hold onto the first base job, was worth -0.4 fWAR, meaning he was below the rate of a replacement-level player.

For additional context, let's look at Cleveland's 2018 season. Ramirez and Francisco Lindor, who both had tremendous seasons, came in at 8.1 fWAR and 7.8 fWAR, respectively. Michael Brantley, who was solid but far below an MVP candidate, had 3.7 FWAR, meaning he was worth 3.7 extra wins over what a replacement player would have given. On the pitching side, Cleveland received strong seasons from four starters: Trevor Bauer (5.8 fWAR), Corey Kluber (5.5), Carlos Carrasco (5.2) and Mike Clevinger (4.2). A newbie named Shane Bieber was worth 2.6 fWAR.

Ryan Lewis can be reached at rlewis@thebeaconjournal.com. Read more about the Guardians at www.beaconjournal.com/sports/cleveland-guardians. Follow him on Twitter at @ByRyanLewis.

This article originally appeared on Akron Beacon Journal: An explanation of Wins Above Replacement and why it's important