Tomlinson Ratings

Every horse whose sire and maternal grandsire have had a meaningful sample of offspring is assigned two Tomlinson Ratings - one that assesses the horse's likely aptitude for grass and one that does the same thing for
muddy or sloppy tracks. These ratings, which have been updated historically twice a year and will now be updated quarterly, are derived from an analysis of tens of thousands of race results on turf courses or wet tracks. The ratings, which appear next to the Turf and Wet headings in each horse's career box, can range from 0 (totally unsuccessful) to 480 (spectacularly successful.