Or, who knows, maybe the sabermetricians are all on strike.
Calculating WAR is simpler than you’d think. If you want the detailed (yet very understandable) version, check out the links at the bottom of the page; Dave Cameron does a good job of walking through the process step-by-step. The short answer, though, is that as follows:
● Offensive players – Take wRAA, UBR, and UZR (which express offensive, base running, and defensive value in runs above average) and add them together. Add in a positional adjustment, since some positions are tougher to play than others, and then convert the numbers so that they’re not based on league average, but on replacement level (which is the value a team would lose if they had to replace that player with a “replacement” player – a minor leaguer or someone from the waiver wire). Convert the run value to wins (10 runs = 1 win) and voila, finished!
● Pitchers – Where offensive WAR used wRAA and UZR, pitching WAR uses FIP. Based on how many innings a pitcher threw, FIP is turned into runs form, converted to represent value above replacement level, and is then converted from runs to wins.
I am not making this up.
[Added] I do love this graphic, though (same source; originally from Beyond the Box Score):