  We study the prophet inequality when the gambler has an access only to a
single sample from each distribution. Rubinstein, Wang and Weinberg showed that
an optimal guarantee of 1/2 can be achieved when the underlying matroid has
rank 1, i.e. in the case of a single choice. We show that this guarantee can be
achieved also in the case of a uniform matroid of rank 2 by a deterministic
mechanism, and we show that this is best possible among deterministic
mechanisms. We also conjecture that a straightforward generalization of our
policy achieves the guarantee of 1/2 for all uniform matroids.
