Model fit of enriched compressed mixed linear model. The model fit (vertical axis) is indicated by twice the negative log likelihood (−2LL). The model fit at different compression levels (horizontal axis) was examined for the 24 combinations (lines with different colors) between the three group kinship algorithms and the eight clustering algorithms. The combination in the standard compressed mixed linear model (average group kinship and un-weighted pair group method with arithmetic mean clustering algorithm) is labeled black. The rest of the combinations are labeled in color. The best combination (with the lowest -2LL) is labeled red. A better combination than the standard compressed mixed linear model was found in all the traits in the four species. OFA, Orthopedic Foundation for Animals.