  In this paper we present "citation success index", a metric for comparing the
citation capacity of pairs of journals. Citation success index is the
probability that a random paper in one journal has more citations than a random
paper in another journal (50% means the two journals do equally well). Unlike
the journal impact factor (IF), the citation success index depends on the
broadness and the shape of citation distributions. Also, it is insensitive to
sporadic highly-cited papers that skew the IF. Nevertheless, we show, based on
16,000 journals containing ~2.4 million articles, that the citation success
index is a relatively tight function of the ratio of IFs of journals being
compared, due to the fact that journals with same IF have quite similar
citation distributions. The citation success index grows slowly as a function
of IF ratio. It is substantial (>90%) only when the ratio of IFs exceeds ~6,
whereas a factor of two difference in IF values translates into a modest
advantage for the journal with higher IF (index of ~70%). We facilitate the
wider adoption of this metric by providing an online calculator that takes as
input parameters only the IFs of the pair of journals.
