Noun
randomizer (plural randomizers)
One who, or that which, randomizes.
On an implementation with an ideal uniform randomizer, the probability at any given time of the next 150 Tetriminos being only S and Z is (2/7) 150 (approximately 2x10 −82 ). Source: Internet
Modern versions of Tetris released after 2001 use a bag-style randomizer that guarantees players will never receive more than four S or Z pieces in a row. Source: Internet
The application is still available online; do a web search for "Garfield" + "randomizer". Source: Internet