tenuki: Nice story, and it even has a happy ending.
Too bad that it is not based on a true one. The point is that if you used the “security number given by a proportion of the gap amongst the player who felt and the one who was saved”, the two bets in Round 22 and 21 in this pond would be DIFFERENT. 1700 is not the same as 2709, therefore your “security number” would not be the same either.