Baseball's Formula for success

Sabermetrics Primer

Bill James has written several books devoted to baseball history and statistics. His approach, which he termed "sabermetrics" in reference to the Society for American Baseball Research (SABR), attempts to use scientific data collection and interpretation methods to explain why teams win and lose, and to help evaluate baseball talent. His fascinating formulations have produced conclusions that often run counter to years of accumulated "baseball wisdom."

Below are some of the innovative statistical measures developed by James:

Runs Created
A statistic intended to quantify a player's contribution to runs scored, as well as a team's expected number of runs scored. Runs created is calculated from other offensive statistics. James' first version of it: Runs Created = (Total Bases * (Hits + Walks))/(Plate Appearances). Applied to an entire team or league, the statistic correlates closely to that team's or league's actual runs scored. Since James first created the statistic, sabermetricians have refined it to make it more accurate, and it is now used in many different variations.

On Base Plus Slugging (OPS)
OPS is calculated by adding On Base Percentage to Slugging Average: (Hits + Walks + Hit-by-Pitch) divided by (At Bats + Walks+ Hit-by-Pitch + Sac Flys) + Number of (Singles + [2 x Doubles] + [3 x Triples] + [4 x Home Runs]) divided by At Bats. This is not a true statistic by definition, but it is often used as an index for rating an overall player's performance and production versus other players.

Range Factor (RF)
A statistic that quantifies the defensive contribution of a player, calculated in its simplest form as RF = (Assists + Put Outs)/(Games Played). The statistic is based on the notion that the total number of outs that a player participates in is more relevant in evaluating his defensive play than the percentage of cleanly handled chances as calculated by the conventional statistic Fielding Percentage.

Win Shares
Bill James invented Win Shares as a method to compare baseball players at different positions, as well as players of different eras. Since the win is the ultimate measure of success, James developed a statistic that measures each player's contribution to his team's wins, or Win Shares. Win Shares incorporates a variety of pitching, hitting and fielding statistics.

Pythagorean Winning Percentage
A statistic explaining the relationship of wins and losses to runs scored and runs allowed. In its simplest form: Winning Percentage equals Runs squared divided by the square of Runs plus Runs Allowed. The statistic correlates closely to a team's actual winning percentage.

Major League Equivalency
A metric that uses minor league statistics to predict how a player is likely to perform at the major league level.

The Brock2 System
A system for projecting a player's performance over the remainder of his career based on past performance and the aging process.

Similarity Scores
Judging a player's qualifications for the Hall of Fame based on his career's similarity to those of other Hall of Famers.

Secondary Average
A statistic that attempts to measure a player's contribution to an offense in ways not reflected in batting average. The formula is (Extra Bases on Hits+Walks+Stolen Bases)/At Bats. Secondary averages tend to be similar to batting averages, but can vary widely, from less than .100 to more than .500 in extreme cases. Extra Bases on Hits is calculated with the formula (Doubles)+(Triples x 2)+(Homeruns x 3).