Range Factor (commonly abbreviated RF) is a baseball statistic developed by Bill James. It is calculated by dividing putouts and assists by the number of innings or games played at a given defense position.[1] The statistic is premised on the notion that the total number of outs in which a player participates is more relevant in evaluating that player's defensive play than the percentage of cleanly handled chances as calculated by the conventional statistic fielding percentage.
However, some positions (especially first baseman) may have substantially more putouts because of a superior infield around them that commits fewer errors and turns many double plays, allowing them to receive credit for more putouts. Also, catchers who have many strikeout pitchers on their team will have a high range factor, because the catcher gets the putout on a strikeout if the batter does not reach base.
Note: All-time single-season leaders are listed according to Range Factor by games played (A + PO) / G. Yearly leaders listed above from 2001–present are listed according to Range Factor per nine innings 9 *(A + PO)/ Inn. Because the latter statistic is unavailable for older players, the former figure is used below to ensure use of comparable data for the all time single season leaders. The figures set forth below are verified from Baseball-Reference.com.
12.65 (Chicago White Sox, 1907)
12.35 (Chicago White Sox, 1908)
12.21 (Boston Red Sox, 1926)
12.10 (Detroit Tigers, 1914)
12.10 (Boston Red Sox, 1918)
7.29 (Chicago White Stockings, 1884)
7.18 (Boston Red Caps, 1879)
7.16 (Chicago White Stockings, 1879)
7.13 (Pittsburgh Alleghenys, 1885)
7.09 (Cincinnati Red Stockings, 1886)
6.73 (Baltimore Orioles, 1895)
6.69 (New York Giants, 1899)
6.62 (Philadelphia Phillies, 1918)
6.56 (Baltimore Orioles, 1896)
6.55 (Baltimore Orioles, 1897)
4.34 (Baltimore Orioles, 1892)
4.33 (Kansas City Cowboys, 1888)
4.31 (Cleveland Spiders/Washington Statesmen, 1891)
4.29 (Chicago Orphans, 1900)
4.26 (Boston Beaneaters, 1896)
5.24 (St. Louis Browns, 1905)
4.97 (St. Louis Browns, 1904)
4.68 (Chicago White Sox, 1907)
4.56 (Cincinnati Red Stockings, 1882)
4.24 (Detroit Tigers, 1904)
4.21 (Chicago White Sox, 1905)
4.20 (Louisville Eclipse, 1882)
4.19 (St. Louis Browns, 1904)
4.14 (St. Louis Browns, 1902)
4.13 (Chicago White Sox, 1904)
9.23 (San Francisco Giants)
8.89 (Chicago Cubs, 2003)
8.64 (Arizona Diamondbacks, 2001)
8.63 (Providence Grays, 1884)
8.32 (Chicago Cubs, 2004)
8.25 (New York Mets, 1972)
8.17 (Atlanta Braves, 1998)
8.06 (Cleveland Indians, 1967)
8.05 (Los Angeles Dodgers, 1997)
8.04 (Houston Astros, 1969)
2.81 (Cincinnati Reds, 1932)
2.78 (Cincinnati Reds, 1930)
2.68 (Pittsburgh Pirates, 1931)
2.63 (Detroit Tigers, 1961)
2.63 (Pittsburgh Pirates, 1977)
2.60 (Philadelphia Phillies, 1930)
2.58 (Pittsburgh Pirates, 1957)
2.57 (Boston Red Sox, 1975)
2.53 (Oakland Athletics, 1982)
3.62 (St. Louis Cardinals, 1928)
3.59 (Philadelphia Phillies, 1951)
3.55 (Chicago White Sox, 1944)
3.55 (Minnesota Twins, 1984)
3.52 (Chicago White Sox, 1977)
3.45 (Washington Senators, 1951)
3.42 (Seattle Mariners, 2003)
3.42 (Philadelphia Phillies, 1949)
3.39 (Boston Braves, 1945)
3.38 (St. Louis Browns, 1935)
3.34 (Philadelphia Phillies, 1956)
2.98 (Philadelphia Phillies, 1893)
2.90 (Cleveland Indians, 1932)
2.83 (Philadelphia Phillies, 1896)
2.76 (Louisville Colonels, 1895)
2.74 (Cleveland Indians, 1928)
2.73 (Washington Senators, 1925)
2.72 (Detroit Tigers, 1921)
2.69 (Philadelphia Athletics, 1949)
2.67 (Chicago White Sox, 1933)