Evaluating Tetris Piece (Tetromino) Randomization Algorithms: Sequence Fairness and Gameplay Impact of Uniform RNG vs 7-Bag Systems

Modern versions of the game use the ”7-bag” randomization technique to soften the sense of bias inherent in extreme pieces “droughts,” where a required tetromino is not generated for a long time. This study compares uniform random number generation (RNG) and 7-bag randomization for two experiments. In the first experiment, we inspected 100,000 produced numbers to severity and homogeneity of distribution. The findings revealed that 7-bag randomization resulted in decreases in maximum Ipiece droughts of 71outcomes. Both techniques maintained the fixed frequencies of pieces in the long run. In the second test, the effect of the game via controlled single-player experiments. Games employing 7-bag randomness raised the average number of cleared squares by 14fewer lines and slightly lower variance, although this was not found to be statistically significant because of the small data set size. In general, the results do prove the quantitative effectiveness of 7-bag randomization in new designs for Tetris.