SPI's Operation Typhoon simulates German attempt to capture Moscow 1941. It uses a variation of the Panzergruppe Guderian system that eventually became the Victory in the West system (including Patton's Third Army, Operation Grenade, and Sicily).This is a big game, three maps but is a very playable monster game and a terrific multi player game. It was the first SPI game to use the concept of variable unit strength. Units are rated for size and morale but actual strengths (fog of war) are determined by drawing a chit randomly at the point where your unit first enters combat. - BoardGameGeek