A. And was he impressed? My S.O. tends to have mixed reactions if I go on about source code too much. It's a fine line. She's an excellent tetris player though, so maybe this would get a pass.

B. I am not a big tetris player (too afraid of the inevitable addiction), but had a game there to see, and am now looking at the source code. ~tetris-allow-repetitions~ just has to be changed to nil, and then it does the correct bag rule behaviour?

C. I wonder why Emacs' tetris default is without the bag rule then... maybe you could submit a patch and propose a tournament? I only learned recently that the platform used for official tournaments is the NES version of Tetris, and now I'm learning that they use the bag rule. Tetris is more serious than I ever knew.

NES Tetris predates the bag rule. The RNG is an 8-sided die with one side meaning "reroll", so it is basically random. That's how you can easily get into droughts of I-pieces for long enough to end a run, and this greatly influences top-level play to encourage "burning" L- and T- pieces instead.

Yes, he did seem impressed. I decided awhile ago that I'm only dating software nerds.