Skat and poker: More luck than skill?

Chess requires playing ability and strategic thinking; in roulette, chance determines victory or defeat, gain or loss. But what about skat and poker? Are they games of chance or games of skill in game theory? This classification also determines whether play may involve money. Prof. Dr Jörg Oechssler and his team of economists at Heidelberg University studied this question, developing a rating system similar to the Elo system used for chess.