  We investigate chaotic dynamics in tree-level S-matrices describing the
scattering of tachyons, photons and gravitons on highly excited open and closed
bosonic strings, motivated by the string/black hole complementarity. The
eigenphase spacing distribution and other indicators of quantum chaotic
scattering suggest that the dynamics is only weakly chaotic, consisting of both
regular/Poisson and chaotic/Wigner-Dyson processes. Only for special values of
momenta and (for photon scattering) scattering angles do we find strong chaos
of random matrix type. These special values correspond to a crossover between
two regimes of scattering, dominated by short versus long partitions of the
total occupation number of the highly excited string; they also maximize the
information entropy of the S-matrix. The lack of strong chaos suggests that
perturbative dynamics of highly excited strings can never describe the
universal properties and maximal chaos of black hole horizons.
