  We compare the $(1,\lambda)$-EA and the $(1 + \lambda)$-EA on the recently
introduced benchmark DisOM, which is the OneMax function with randomly planted
local optima. Previous work showed that if all local optima have the same
relative height, then the plus strategy never loses more than a factor $O(n\log
n)$ compared to the comma strategy. Here we show that even small random
fluctuations in the heights of the local optima have a devastating effect for
the plus strategy and lead to super-polynomial runtimes. On the other hand, due
to their ability to escape local optima, comma strategies are unaffected by the
height of the local optima and remain efficient. Our results hold for a broad
class of possible distortions and show that the plus strategy, but not the
comma strategy, is generally deceived by sparse unstructured fluctuations of a
smooth landscape.
