Between 1871 and the end of the 2007 season, major league batters have hit safely 3,436,129 times in 13,098,551 at bats, for a cool .262 batting average.
As for the postseason, since the 1903 World Series (again through 2007) batters have only hit .245, going 19,718 for 80,594. Maybe Yankees fans should go easy on A-Rod*.
In regular season MLB games, Jimmie Foxx hit .325
Ty Cobb had a lifetime batting average of .366
194
His lifetime Batting Average is .109, he was 54 for 497.
Ty Cobb with a .366 batting average
24
Ty cobb has the highest career batting average at .366
.366 average by Ty Cobb
Chipper Jones
.302
.293
Sisler's lifetime average was .340 over a career that spanned 1915-1930.