1. c2c4  1... e7e5  2. b1c3  2... g8f6  3. g1f3  3... b8c6  4. e2e4 This system is very popular nowadays. It was used, for instance, by Niemann in his victory against Mamedyarov in the Sinquefield Cup. 4... f8b4 Mamedyarov chose 4...Bc5, a more combative move that leads to complicated positions. The move played by Duda is more reliable. 5. d2d3  5... d7d6  6. a2a3  6... b4c5 I played many online games with White in this system, and many of my opponents preferred to play 6...Bxc3. Of course, it's too much criticism to call this capture a mistake, but it makes White's play much easier with the bishop pair, good central control, and a clear plan of attack on the kingside. 7. b2b4  7... c5b6  8. c1e3  8... c8g4  9. f1e2  9... e8g8 