I don't know too much about SABR stats and all of that, but I've always been interested in learning more about them. Now I have a question about WAR: is there a defined value for a replacement player? Like are there certain stats that correlate to what a replacement player would contribute, and therefore make it plausible to define how much more valuable someone is than one?
My issue is that the term "replacement player" means different things to different teams and therefore players. For example, Tampa Bay consistently loses top players and doesn't miss a beat. This is because of how well run the organization is and how deep their farm system is. A "replacement" player can come in and replace someone like Carl Crawford or Evan Longoria and the team might be only a game or two worse. Obviously those guys aren't 1-2 WAR guys. Tampa's replacement players are much better than average. Meanwhile take a team with a horrible farm system. If they called someone up that player might be far worse than an average replacement player. That means different players have different standards, and while that actual stat of WAR might not be affected (as it is calculated through individual stats) it may lose some of its meaning.
So basically my question is what statistically, if anything, defines a "replacement player", and other than ruining the acronym, wouldn't the stat be more useful if it was something like "wins above average player"? Is that what it already is and I'm just confusing myself? Again, I know very little about SABR, just trying to clarify this.