Four CPU bosses follow the seven main opponents in Street Fighter II’s single-player mode.
The original Street Fighter II begins with a roster of eight playable fighters. In the tournament, the player selects one character and fights the other seven main fighters. After those matches, the game sends the player against four bosses known collectively as the Grand Masters.
The four bosses are Balrog, Vega, Sagat, and M. Bison. They were CPU-only opponents in the original version, unlike the eight main fighters. Later updates, including Champion Edition, made the four bosses playable and allowed players to choose from a larger roster.
This structure is easy to misremember because the game has eight selectable characters but twelve total tournament opponents. The count asked for is the number after the seven ordinary matches: four bosses.