The Colle System Koltanowski Variation: 5. c3
1.d4 d5 2.e3 Nf6 3.Bd3 e6 4.Nf3 c5 5.c3 and other moves where Black does not play c5. There aren't as many strategic plans and positional themes as in the Queen's Gambit; but there are still quite a lot - and that's enough for 95 percent of serious players. Against an amateur opponent, the Colle is a deadly weapon, a quick killer. Edgar Colle and his fellow Belgian native, GM George Koltanowski, registered a string of sparkling victories, many of them in less than thirty moves, with this system. He even had the great Alekhine on the ropes with it.