My Favorite Advanced Baseball Statistic

My favorite advanced statistic in baseball is WAR.  It stands for "wins above replacement".  It's gotten a lot of coverage this year due to the MVP race between Miguel Cabrera and Mike Trout.

The calculation of the WAR statistic is relatively complex, but the idea behind the statistic is simple.  How much is a player worth above a replacement quality player?  (A replacement player is generally considered to be a high quality minor league player or perhaps a bench player).

The statistic is normalized around 0.  If a player's WAR value is > 0, the player is performing better than a replacement player.  If the player is performing < 0, a team would be better off replacing that player with a replacement player.

I love this statistic because of what it represents.  So much decision making in our lives comes down to a simple judgement of "Can I do better?".  For example:

• Hiring Employees: "Sally is a good candidate, should we hire her or keep on interviewing more candidates?
• Firing Employees: "Joe is a bad performer, but still accomplishes a lot of stuff.  Should we keep him?"
• Job: "Company A has a ton of problems, should I stay or go?"
• Job offers: "Company X just offered me Y thousand a year.  Should I take this offer?"
• Dating: "Suzy is a great gal, but is she the right one for me?"

Unfortunately, in the normal world, its far more difficult to calculate a statistic for "current value" vs. "replacement value", but it's what we do in our heads all the time.