nimzovich was the founder, and alekhine, tartakower, réti, grünfeld, and bogolyubov all took part. all were top grandmasters of the 1920s and 30s. several modern openings owe their popularity to this group: alekhine's defence (1e4 nf6); réti's opening (1nf3); the king's indian defence (1d4 nf6 2c4 g6 3nc3 bg7); the grünfeld defence (1d4 bf6 2c4 g6 3nc3 d5) and the modern defence (1...g6).p178