Conversation so far:
What did Steffi play?
CANNOTANSWER.
what was her play style?
The main weapons in Graf's game were her powerful inside-out forehand drive (which earned her the moniker Fraulein Forehand) and her intricate footwork.
what else represented her play style?
Graf's technique on the forehand was unique and instantly recognizable.

Question: why did she use this style?
Self-contained rewrite: why did Steffi use inside-out forehand drive style?