Anyone that likes to handicap the races and takes it in a more serious manner will go back and review the charts of past performances. I used to download the charts and store them on my hard drive because the sites usually only posted the charts for a certain amount of time. The link below will allow you to research charts going all the way back to 1991. They have almost every track that runs in North America.
http://www.equibase.com/premium/eqbR....cfm?refresh=1