The internal NES clock must accurately measure down to milliseconds for its games to work properly. 2023 December 1, Evelynn Kersting, “GAMES AND TIME”, in University of Wisconsin-Milwaukee, archived from the original on 07 Jun 2025, page 11, archived from the original on 06 Jun 2025:
The strategy that has dominated recently for the last couple of years is to tap the d-pad as fast as humanly possible with one finger, known as hypertapping in the gaming community. In NES Tetris, this skill is crucial, since the speed increases when moving up levels, culminating in level 29, where the pieces usually drop to the bottom of the board in less than ⅓ of a second. However, hypertapping has several limitations. 2021 June 16, Tzvi Kalb, “What is Old is New Again: NES Tetris”, in The Science Survey, archived from the original on 03 Jul 2022: