wOBA weights each game event by the ability to produce runs. By weighting each possible outcome of a plate appearance, one can get a true measure of offensive production. The weights of particular situations vary from year to year. A double might be worth a certain amount of runs one year but a different amount the next. The value of the play is determined by the environmental factor for that particular season. For example, in a high scoring season or stadium, it is more likely that a single or double will produce a run than in a lower scoring season/stadium. Whatever is causing this spike in runs, whether it be the pitching that season or something else, makes is more likely that the upcoming hitter will be able to drive in the run. A player might have a higher OPS than another player yet have a lower wOBA than that same player. This is because wOBA takes into account baserunning and places a higher importance on OBP.

As interesting as wOBA might seem, it is only the primer for the more important statistic, weighted runs above average, or wRAA. wRAA measure the number of offensive runs a player contributes to a team. Zero denotes the league average, so anyone contributing a positive value is an above average hitter. wRAA is a counting statistic like runs, so players accrue as the season goes on. It can be calculated by simply using the following formula: wRAA = ((wOBA-league wOBA)/Scale)*Plate Appearances. The scale is used to account for different run environments and is usually around 1.15. Since the number is adjusted so you can use it to compare players from different leagues and years.

Looking at wRAA since 2000, the names at the top of the list will not surprise you: Albert Pujols, Barry Bonds, Alex Rodriguez, Todd Helton, Manny Ramirez, Lance Berkman, Chipper Jones. Pujols has contributed 616 runs to his team since 2000. Jones, who ranks 7th on this list, has contributed 393. This gives a great idea of just how special of a player Pujols has been for the Cardinals. Now for the fun part. Cristian Guzman has taken away 107 runs since 2000. Omar Visquel, as good of a fielder he has been, has taken away 91 runs. The other three players who have taken away more than 80 runs are Yuniesky Betancourt, Jose Lopez and Orlando Cabrera.

For the 2011 season only, as expected Jose Bautista leads the majors with 38 runs contributed. Other top names on the list are Matt Kemp, Prince Fielder, Joey Votto and Adrian Gonzalez. It should not surprise you that these players are the ones most commonly talked about as having stellar seasons. Looking at the other side, Chone Figgins has been the most worthless hitter in baseball, taking away 19 runs. Miguel Tejada, Alcides Escobar, Alex Rios, Mark Ellis and Dan Uggla have all taken away more than 12 runs.

In the last two weeks, we have gone over how to most accurately measure the performance of a player not only at the plate but also in the field. Next week, we’ll combine these two statistics and discuss the one stat that gives us the most telling reflection of overall player performance.