What I don't understand is - if the two parts of the tally stick presented don't match, what do you do then? How do you resolve that? How do you know which party is the one in error?
How's that? If I throw away my old half, split a new one, and add fewer cuts to it, you'd apparently assume it was the legitimate one, but it wouldn't be.
Lol but which is the original?
That's the point.
If you have two that don't match you don't know which one is the legitimate one you just know that they don't match and at least one is not legitimate.
1. Have an artisan make the sticks. These required tools to make, and I don't know how prevalent the tools were, so it's entirely possible that it would be completely infeasible for anyone not the local carpenter to make these sticks, and would also make him a sort of arbitrating third party.
Otherwise you, as the debtor, could just throw your stick away, claim the creditor's is false, and be done with it.