Sometimes players need to gain time on the clock by repeating the position, but most often its purpose is to wear down the opponent psychologically.
Pal BenkoWhen you defend, try not to worry or become upset. Keep your cool and trust your position - it's all you've got.
Pal BenkoI remember being with a girlfriend who asked me to look over some chess openings with her. I instantly fell asleep. I found that I could always take a nap in any situation by just looking at some opening variation - my eyes would shut right away.
Pal Benko