If you are in this situation you have the practical reality that paying the $100 loses you $100 and a theoretical argument that you should pay anyway. If you apply “just ask which algorithm wins” and you mean the practical reality of the situation described, then you wouldn’t choose UDT. If you instead take “just ask which algorithm wins” to mean setting up an empirical experiment, then you’d have to decide whether to consider all agents who encounter the coin flip, or only those who see a tails, at which point there is no need to run the experiment. If you instead are proposing figuring out which algorithm wins according to theory, then that’s a bit of a tautology as that’s what I’m already trying to do.
If you are in this situation you have the practical reality that paying the $100 loses you $100 and a theoretical argument that you should pay anyway. If you apply “just ask which algorithm wins” and you mean the practical reality of the situation described, then you wouldn’t choose UDT. If you instead take “just ask which algorithm wins” to mean setting up an empirical experiment, then you’d have to decide whether to consider all agents who encounter the coin flip, or only those who see a tails, at which point there is no need to run the experiment. If you instead are proposing figuring out which algorithm wins according to theory, then that’s a bit of a tautology as that’s what I’m already trying to do.