How many balls do players use in Russian pyramid?

Russian pyramid, also known as Russian billiard, is a form of pocket billiards played on a table similar to a snooker table. It is popular across Eastern Europe as well as countries of the former Soviet Union/Eastern Bloc. A variant with colored balls modeled on those of pool is known as Russian pool. In Western countries, the game is known as pyramid billiards, or simply pyramid within professional circle. Russian pyramid is considered to be one of the most difficult billiards games.

There are sixteen balls (fifteen numbered balls and a cue ball), as in pool, but the numbered balls are white, and the cue ball is usually red or yellow. Up to 70 millimetres (2 3⁄4 inches) in diameter, they are larger and heavier than Western billiard balls; the official tournament size is 68 mm (2 11⁄16 in). Smaller balls – e.g., 63 mm (2 1⁄2 in), 60 mm (2 3⁄8 in), and 57 millimetres (2 1⁄4 in) (regular pool ball size) – are available for the smaller table sizes.