Doubles occur when a batter hits a fair ball and reaches second base without reaching due to a fielders error or a fielders choice. Doubles are the second most common type of hits in baseball and generally make up approximately 20% of all hits in a season. Doubles leaders generally hit between 40 and 50 doubles in a season.
More about Doubles Leaders
Occasionally the doubles single season record of 67 (set by Earl Webb in 1931) is threatened though a player hasn’t even hit 60 since 1936. Doubles leaders are often likely to include power hitters who also hit a lot of home runs, as hitting home runs also leads to getting a lot of hits deep into the gaps that don’t quite clear the fences.