The title says it all. What is the average number of baseballs used in a 9 inning game?
This question doesn't have an exact answer but there are many articles which suggest, for a particular (9 innings) game , on avergage 8 to 10 dozen baseballs are used.
According to the Pirates' equipment manager, an actual game between the Pittsburgh Pirates and Milwaukee Brewers, used 104 baseballs.
Which is just above 8 dozen balls.
From a foxsports.com article according to Twins assistant equipment manager Tim Burke,
On any given night, teams will go through 100 baseballs or more, which equates to just a few pitches per ball.