Local LD decay rate () and LD ( r2) in different window sizes. The figures show effects of different window sizes on the estimates of and expected r2, illustrated with Chromosome 1, Duroc. (a) is a plot of for each sliding window against the physical position (in Mb) of the middle point SNP in this window, and (b) is a plot of the expected by and d = 10 Mb against middle point SNP position (in Mb). The window sizes are 50, 100, 200. The grey horizontal line represents the mean for whole Chromosome 1.