Before anyone asks, yerk is a real word and its meaning can be found here. As for Yugoslav I already covered the Yugoslav Attack against the Dragon under its other name, the Rauzer Attack, so this time I will look at the Yugoslav System against the fianchetto King’s Indian in which Black plays …c7-c5 instead of …e7-e5. The moves are 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 0-0 5.Nf3 d6 6.0-0 c5 and now Black meets 7.d5 with 7…Na6 (intending …Nc7 followed by playing for …b7-b5) and 7.Nc3 with 7…Nc6.
This system got its name thanks to the efforts of Yugoslav players and analysts, most notably Svetsovar Gligoric. Gligoric was an outstanding specialist in the King’s Indian and contributed numerous new and dynamic ideas, but it was perhaps in this system that his influence was the greatest. Here is a flowing example in which he annihilates one of the top American players: