Any knucklehead can see that Rickie Weeks is absolutely mashing the ball. But it takes a more sophisticated analysis to determine whether Weeks and other Milwaukee Brewers are earning their keep.
That was the goal of Michael Lewis' 2003 book, Moneyball. It chronicled attempts by some major league operations to take regular baseball numbers, combine them with economic principles, and find a way to objectively evaluate players.
The OPS, which combines a player's on base percentage (OBP) with his slugging percentage (SLG), is a perfect example. This stat highlights disciplined players who can also hit for power.
Take Brewers center fielder Mike Cameron. His batting average of .293 is nice, as is his .389 OBP. But thanks to six homeruns and 10 doubles, he's slugging .598 (he's averaging just under six bases in every 10 at bats), tops on the team. Same goes for his OPS of .987, which is well above last year's .808. Ryan Braun is right behind him with .955, followed by Prince Fielder at .870.
Meanwhile, Weeks' six homers are impressive, but his 25 strikeouts make his OPS a relatively mediocre .808.
If Cameron can stay healthy and maintain those numbers, he'll compile a high VORP, which stands for value over replacement player. This indicates the number of runs a player is worth to his team beyond what a low-salary sub would score in the same number of plate appearances.
Of course, some of these stats are influenced by what is known in the field as "sub-optimal decision making," or what the rest of us call boneheaded managing.