Regarding the randomizer article: Tetris requires some randomness, but also some prevention of "floods" and "droughts". This sounds remarkably like the use of b

Regarding the randomizer article: Tetris requires some randomness, but also some prevention of "floods" and "droughts". This sounds remarkably like the use of blue noise in dithering. Unlike purely random white noise, blue noise optimizes for "even" sequences without too many repetitions or large gaps in occurrences. I assume a similar thing is possible in a randomizer, which would make more even sequences of draws more likely than ones which are less even. Of course perfectly "even" distributions would no longer be random at all (each of the seven pieces would reoccur after exactly seven steps), but one could make anything else just less likely, depending on how far it deviates from the most likely seven step reoccurrence.