Joe Jackson (Shoeless Joe) with a .340 batting average for the White Sox between 1915-1920.
Riggs Stephenson and Bill Madlock are tied for the Cubs career batting average leader with .336.
Tony Armas of the Red Sox had the lowest batting average for an RBI leader. He had 107 RBIs and a .218 batting average.
The single postseason batting average leader is Lloyd McClendon with 16 plate appearances, he batted .727 in the 1992 postseason.
Hall of Famer Charley Taylor who ended his career with 649 pass receptions.
For MLB, the all time leader in triples is Sam Crawford, who played from 1899-1917, with 309.
Ty Cobb with a .366 lifetime average. The single season leader is Hugh Duffy at .4397 in 1894.
http://www.imdb.com/name/nm0395202/bio Rogers Hornsby, with a .359