Malecot's method of coancestry

Malecot's coancestry coefficient, f {\displaystyle f} , refers to an indirect measure of genetic similarity of two individuals which was initially devised by the French mathematician Gustave Malécot. f {\displaystyle f} is defined as the probability that any two alleles, sampled at random (one from each individual), are identical copies of an ancestral allele.