  We consider a situation where one has to choose an option with multiplier m.
The multiplier is inversely proportional to the number of people who have
chosen the option and is proportional to the return if it is correct. If one
does not know the correct option, we call him a herder, and then there is a
zero-sum game between the herder and other people who have set the multiplier.
The max-min strategy where one divides one's choice inversely proportional to m
is optimal from the viewpoint of the maximization of expected return. We call
the optimal herder an analog herder. The system of analog herders takes the
probability of correct choice to one for any value of the ratio of herders,
p<1, in the thermodynamic limit if the accuracy of the choice of informed
person q is one. We study how herders choose by a voting experiment in which 50
to 60 subjects sequentially answer a two-choice quiz. We show that the
probability of selecting a choice by the herders is inversely proportional to m
for 4/3 < m < 4 and they collectively adopt the max-min strategy in that range.
