The Post Time Daily past performances provide two Sire Ratings ¹ for each runner, Off-Track and Turf, which measure that runner's likelihood of success on those respective surfaces.

The algorithms used in calculating the Sire Ratings are proprietary to Post Time Daily. Each of a runner's sires (sire, grandsire and damsire) is assigned a rating based on that sire's proclivity in producing horses which run well on the given surface. The three sires' ratings are then combined to produce a single value for today's runner. Each sire's ratings are recalculated each month based on the performance of their offspring.

It is important to note that the Sire Ratings are intended to be used with runners who have few, if any, starts on the given surface. Once a horse has established itself on a given surface, reliance on that horse's actual performance, as opposed to their pedigree, is strongly recommended.

Turf ratings will typically range between 70-270, with a 220+ rating being noteworthy. Higher class races will often produce more runners with higher ratings. It's also important to note that, more important than the actual rating, is any "gap" between the top-rated runner and the rest of the field. A horse with a 15+ point advantage over the rest of the field can be considered significant.

Off-track ratings will typically range between 100-280, with a 250+ rating being noteworthy. As with Turf Ratings, any gap from the top-rated runner to the rest of the field is especially important. For Off-Track Ratings, a gap of 20+ points is considered signifcant.