That was somehow answered in:
That’s pretty much it @ScotterMonkey ’s case, 3rd word, so that would be 2
When you run the script you will get all the words that could fit in that gap and still pass the checksum.
But : The script is for old 12 word phrases.
I have written a script with the same idea that works with 12, 15, 18, 21, or 24 word phrases:
I have reimplemented @isferos ’ idea in Python 3 for a flexible length seed length (12, 15, 18, 21, or 24 words):
It is called with the words that you know as command line arguments and _ as placeholder for words you do not remember.
If the last word of a 15 word Yoroi seed phrase is missing, it will give you exactly 64 possibilities (the last word encodes 11 bits, of which 5 bits are checksum, so 6 bits are part of the entropy and 2^6=64). For missing words in other places, the order of magni…
Also, in contrast to @isferos ’ script it takes the words on the command line. So you don’t have to change the script and risk (part of) your seed lying around on disk.