A

baseball statistic created by

Bill James as one of the first attempts to calculate a hitter's total value to his team. Fairly complicated to calculate (in its most technical version), but also more accurate than any of the typical counting or percentage stats used in baseball (with the possible exception of

OPS).

The basic formula for runs created is {(Hits + Walks) * (Total Bases)} / (At Bats + Walks). A more complicated version is

**(H + W - CS + HBP - GIDP) * (TB + (0.26 * (W - IBB + HBP)) + (0.52 * (SH + SF + SB))) / **

(AB + W + HBP + SH + SF).

This formula gives the number of runs created by a given player. For example, Babe Ruth in 1921 "created" 238 runs, the best season of all time by this measure. Mark McGwire in 1998 created 193 runs, good for 18th place. These numbers are hard to interpreted by themselves; the best way to see what they mean is to compare them to a) the number of outs the player created, and b) the league average.

If you take the runs created for a player and divide it by the number of outs the player created:

**(AB - H) + CS + GIDP + SH + SF **

and multiply by 27, you get runs created per 27 outs; that is, the number of runs a lineup of nine copies of this player would score in a given game. By comparing this to the league average for runs per game, you can see how much better (or worse) a player was than his league during that season.

Recently, many other statistics have been created attempting to measure a hitter's worth; many of them are at least as statistically difficult, such as Baseball Prospectus' Equivalent Average. Bill James himself has tinkered with and made improvements to his original formula (making more complicated and more accurate). A much simpler formula, although slightly less accurate, is OPS, which stands for the formula, On Base Percentage Plus Slugging Percentage. The large advantage of the simpler formula (especially since OBP and SLG are given with almost any set of statistics for a player) is making OPS a popular statistic for quickly evaluating and comparing players.

**OBP = (H + W + HBP) / (AB + W + SH + SF)**

SLG = TB / AB

AB = At Bats

CS = Caught Stealing

GIDP = Grouded Into Double Play

H = Hits

HBP = Hit By Pitch

IBB = Intentional Base on Balls

SB = Stolen Bases

SF = Sacrifice Flies

SH = Sacrifice Hits/Bunts

TB = Total Bases

W = Walks