RC (runs created): An estimator of how many runs a batter produces for his team, created by Bill James.
“Basic”: ((H + BB) * (1B + (2*2B) + (3*3B) + (4*HR))) / (AB + BB)
“Technical”: ((H + BB – CS + HBP – GDP) * ((1B + (2*2B) + (3*3B) + (4*HR) + (.26 * (BB – IBB + HBP)) + (.52 * (SH + SF + SB)))))/ (AB + BB + HBP + SF + SH)
Which formula and when: FanGraphs employs both formulas depending on what stats are available for individual seasons. Seasons prior to 1955 use the “Basic” formula and any season after and including 1955 uses the “Technical” formula.
Why you should care: Runs Created is a good estimator of how many runs a team should have scored in a given season. When applied to players, it is somewhat less accurate though still a useful estimator of a player’s actual production.
Variations: There are other run estimators that do a better job then Runs Created, yet one of the main advantage of Runs Created is that it’s extremely easy to calculate. Other run estimators include: Batting Runs, Base Runs, Extrapolated Runs, Estimated Runs Produced, Equivalent Runs.
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