Advanced baseball statistics can be hard to understand and often contain more acronyms than the New Deal. Here is a list of 12 terms that are widely used with an explanation of what they measure.
WAR (or WARP, wins above replacement player)
WAR attempts to encapsulate the value of all players across all positions for a season: How much better or worse is a player than a theoretical call-up a team has waiting in the wings? And how many wins did he add to his teams total that season compared to if he wasnt in the lineup? It takes into account a players offense, defense and base running. Pitchers WARs have their own metrics. Three websites, Fangraphs, Baseball Reference and Baseball Prospectus, have different variations of this statistic. They differ the greatest in what metrics (some of which are on this list) they use to calculate a players defense and how they evaluate pitchers. So a players WAR on one website can be different than the others.