Right, so you need a more restrictive equilibrium concept than subgame-perfect equilibrium. It&#x27;s a good math exercise to try fleshing out exactly which concept is implied by your common sense reasoning (which I&#x27;m not arguing against!) Some folks have suggested trembling hand equilibria and other ideas, none of which are obvious from a naive reading of the problem.<p>Maybe it&#x27;s more helpful to think about such problems in terms of &quot;how would I write a program to solve all problems in this class?&quot;, rather than &quot;how would I act using common sense in this particular problem?&quot; That often makes things clearer.