Jewish players and theoreticians have long been involved in the game of chess and have significantly contributed to the development of chess, which has been described as the "Jewish National game". Although Jews make up less than 0.2% of the world's population, of the first 13 undisputed world champions, over 50% were Jewish, including the first two. The Modern school of chess espoused by Wilhelm Steinitz and Siegbert Tarrasch; the Hypermodernism influenced by Aron Nimzowitsch and Richard Réti; and the Soviet Chess School promoted by Mikhail Botvinnik were all strongly influenced by Jewish players. Other influential Jewish chess theoreticians, writers and players include Zukertort, Tartakower, Lasker, Rubinstein, Breyer, Spielmann, Reshevsky, Fine, Bronstein, Najdorf, Tal, Fischer, and Pol