Yes
In MLB, that is Stan Musial of the Cardinals against the Giants on May 2, 1954 and Nate Colbert of the Padres against the Braves on August 1, 1972 .... each hit 5 home runs during a doubleheader.
My baseball team played a doubleheader
the 1961 Philadelphia Phillies, losing 23 straight from July 29th through the first game of a doubleheader on august 20th.
yes because they used drugs to get the records
The longest doubleheader, timewise, in MLB history was in 1995 between the Chicago White Sox and the Texas Rangers which lasted 7 hours 39 minutes.
oldest player to pitch in the mlb
September 18, 2003 when the Orioles and Yankees tied 1-1. The game was called after 5 innings because of rain and was made up as part of a doubleheader on September 26.
Barry Bond
twofold doubleheader
They have a playoff
yes