One often uses the average citation impact factor in order to perform
international comparisons between the levels of scientific performance
within given disciplines. In averaging over all (or all cited) papers
one may give undue weight to papers with few citations while, in fact
, the standing of a country within a given field would be better asses
sed by looking only at the ''successful'' papers in that discipline. T
he present papers suggests that one should do so by averaging citation
s only over the ten (or twenty) percent of the most cited papers in a
discipline and use these in order to establish a ranking between count
ries. The case of Israel is used as an illustration of this approach.