 However, the bookie can guarantee himself a profit in some cases even if it is not assumed that the agent will follow though by placing a side bet that he wins in the event that the agent does not change beliefs as planned. The Dutch Strategy depends upon the fact that the agent initially has some definite probability that he will shift probabilities in the event that \(E\), in some particular way that is not the result of conditionalization on \(E\). The Dutch Strategy argument in no way establishes that one must have such a probability, and so at most shows that one should not have a plan involving a fixed probability to update upon learning \(E\) in a way that differs from conditionalizing on \(E\).