Score distributions for (RQGS) and (FQPS) models. Score distributions for (RQGS) (classical) and (FQPS) models where the subject length equals the query length. In order to compare the shape, the distributions have been shifted by the center s0. (a): Linear view; all distributions from the (RQGS) agree outside the tails (only two lengths are shown). The shape of the (FQPS) distributions is more variable. (b): Logarithmic view; significant differences between the two models appear in the tail of the distribution. High scores are more probable for the (FQPS) alignment. Furthermore the curvature, i.e. the deviation from the Gumbel form, is much larger for (FQPS) than for the classical model.