One of the popular cold storage wallets provides double-sided tiles for users to put in the first four letters of each of their 24 words (96 characters total).
They include ~245 double sided tiles, plus some blanks.
By my math on the BIP39 wordlist, they should need to provide ~485 double sided tiles to provide for every valid 24 word mnemonic.
I simply calculated, for each letter, the worst case 24 word combination, then added up how many of each letter I would need, then divided by 2 since the tiles are double sided.
Is there something I’m missing here?
EDIT I have found at least one flaw in my reasoning. The last word is a checksum, so not entirely random. But accounting for this only saves us 33 letter tiles!