Minor league baseball MLB free agency puts the “R” in WAR

DENVER, CO - SEPTEMBER 17: Erick Aybar
DENVER, CO - SEPTEMBER 17: Erick Aybar /
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Minor league baseball
Minor league baseball /

Minor league baseball MLB free agency signings are a good proxy for the replacement level in Wins Above Replacement.

While there are still holdouts against Wins Above Replacement (WAR), it’s clear that WAR is here to stay. It’s used by analysts, of course, but also by fans and announcers. Even many Hall of Fame voters have embraced it. More and more, it’s becoming a reference point in baseball conversations. It may not be perfect, but to dismiss it out of hand is like rejecting CDs and clinging to cassette tapes in the 1980s or dismissing DVDs in favor of VHS tapes in the 1990s. It’s also useful when determining the future of MLB, with its Minor league baseball prospects.

Fangraphs defines WAR as “an attempt by the sabermetric baseball community to summarize a player’s total contributions to his team in one statistic.” It’s a way to value a player for everything he does, which is something baseball fans have been doing in their heads for years. WAR is meant to do objectively what fans have been doing subjectively.

You might have argued with a friend over which player is better, perhaps your favorite player versus her favorite player. If it’s a position player, you’ll talk about how well he can hit, if he can steal bases, and if he’s any good in the field. WAR combines all of this information into one number. If you look at the WAR leaderboards for a single season, you’ll find the best players in the game that year. If you look at the career leaders in WAR, you’ll see the all-time greats, like Babe Ruth, Barry Bonds, Willie Mays, and Walter Johnson.

The specifics of WAR were not chiseled into stone and presented as a finished product. The framework is foundational, but the specifics can be adjusted based on new information. Five years ago, there was a notable advancement in the metric when the two main versions of WAR, Fangraphs, and Baseball-Reference, agreed on a unified replacement level.

Replacement level is the “R” in WAR. As defined by baseball analyst Tangotiger, replacement level is “the talent level for which you would pay the minimum salary on the open market, or for which you can obtain at minimal cost in a trade.” Tango had replacement level equal to a .292 winning percentage in his blog post from 2008.

Before the grand unification five years ago, the Fangraphs replacement level was at .265 and Baseball-Reference was at .320. They came together and agreed upon .294. Essentially, this means that a team of replacement-level players would have a .294 winning percentage, which is a record of approximately 48-114 in a 162-game MLB season (see this link for the similarities and differences among Fangraphs WAR, Baseball-Reference WAR, and Baseball Prospectus WARP).