The highly acclaimed SOS series provides intermediate chess players with perfectly playable, easily digestible opening ideas: deviations from main line opening theory in a very early stage of the game (usually before move six). Anyone with a rudimentary knowledge of the chess opening will be able to apply these SOS-ideas in an actual game. There is no need to study large quantities of stuffy theory, but there is an almost immediate return on the investment of a limited amount of time. Readers of SOS will baffle their opponents, gain crucial time, and stand a good chance to get an advantage in the game.