The Astros have had a rough past few years searching for talent. A lousy minor league system and the inability to develop talent properly have led to many trades of their so-called "stars." Arguably the best piece they got in return from one of Wade's blockbuster deals has been Michael Bourn.
Having been worth 4+ wins each of the last two seasons as well as being easily the best defensive outfielder in the NL, the 'Stros certainly have a cornerstone type of talent. What's really underrated is how much he helps the team on the bases.
OPPS is a statistic used to quantify the total baserunning opportunities of a certain player. The formula is GA_OPPS(ground advancement opportunities) + SB_OPPS (stolen base opportunities) + AA_OPPS(air advancement opportunities) + HA_OPPS(hit advancement opportunities) + OA_OPPS (other advancement opportunities), as stated by Baseball Prospectus. In other words, it's more of a quantifying type of statistic than a pro rate or an average type.
As BP also states, "Equivalent Base Running Runs. Measures the number of runs contributed by a player's advancement on the bases, above what would be expected based on the number and quality of the baserunning opportunities with which the player is presented, park-adjusted and based on a multi-year run expectancy table. EqBRR is calculated as the sum of various baserunning components: Equivalent Ground Advancement Runs (EqGAR), Equivalent Stolen Base Runs (EqSBR), Equivalent Air Advancement Runs (EqAAR), Equivalent Hit Advancement Runs (EqHAR) and Equivalent Other Advancement Runs (EqOAR)."
Alas, being 11th in 2010 according to OPPS (at 566) and then leading in EQBRR displays the success of Bourn on the basepaths when the ball is put in play or when he advances 90 feet by himself. Of course, with a lnieup that didn't do much offensively in 2010, Bourn made the most of his opportunities while getting on base fewer times than several others, while leading by a big margin in EQBRR.
In case you were interested, Juan Pierre, Brett Gardner, Angel Pagan, Elvis Andrus, Carl Crawford, Andrew Torres, Emilio Bonfacio, Austin Jackson, and Shane Victorino were the next 9 in EQBRR. In terms of OPPS, the 10 in front of Bourn were (from 10th to 1st) Carl Crawford, Marco Scutaro, Daric Barton, Elvis Andrus, Rickie Weeks, Denard Span, Austin Jackson, Derek Jeter, Juan Pierre, and Ichiro.