VORP

From Wiki Gonzalez

VORP stands for Value Over Replacement Player, a Baseball Prospectus statistic that measures "the number of runs contributed beyond what a replacement-level player would contribute if given the same percentage of team plate appearances."

Note that, while VORP is an adjusted statistic, it is a counting stat and not a rate stat.

VORP uses MLV, adjusted to replacement level, and adjusted for park effects and position for position players, and runs allowed for pitchers.

In the past Baseball Prospectus set replacement level for VORP at:

• 70 points of OPS below league positional average for position players
• 1 RA above league average RA for pitchers

More recently they've moved to VORP replacement level at:

• 80% of the average offensive rate (85% is used for catchers, 75% is used for 1B/DH) for position players
• 1.37 * League RA - 0.66 for starting pitchers
• 1.70 * League RA - 2.27 for relief pitchers

References

• Baseball Prospectus (http://baseballprospectus.com/glossary/index.php?mode=viewstat&stat=186)
• Introduction to VORP: Value Over Replacement Player by Keith Woolner (http://www.stathead.com/bbeng/woolner/vorpdescnew.htm)
• VORP: Measuring the Value of a Baseball Player's performance by Keith Woolner (http://www.stathead.com/articles/woolner/vorp.htm)