From the Introduction area elsewhere on this site:
\"Each number on a \"sheet\" represents a performance rating calculated by using the time of the race, beaten lengths (a proprietary formula different than generally used), ground lost or saved, weight carried, and the effect wind may or may not have had on the time of the race. The final figure is manually adjusted with a carefully crafted track variant. The lower the number the better the race. With few exceptions, there will be a figure for every race a horse has run past four years.
Thoro-Graph figures are represented in a clear graphical format. This format makes it possible to compare horses which have run under different conditions, different distances, at different tracks, and on different days. Any handicapper or horseman can examine each horse\'s history, form cycle, and relative ability in today\'s race.\"
Lots of great stuff on this website, and some very sharp handicappers that post regularly(I\'m here to listen and learn.)