I don\'t tie one and two turn races together, so pars are not an issue here, and there are very few 2 turn dirt races at Belmont. You make the figures off the horses in the race itself (you might get some help from the surrounding days if they ran 2 turns, but that would just be an indication), but the good news is that horses who run that far usually have a significant figure history, distance horses are pretty consistent, and stake horses especially so.
To show you what I mean, go back and look at the sheets for the Derby and Preakness horses, still available on this site, and look at them as one race cards-- as if they were the only race on the day. You will see that adding or subtracting doesn\'t work-- the variant is solid, without any help from other races.
The killer ain\'t the Belmont-- it\'s the rained off grass marathon with 5 horses without solid dirt form, only 2 turn race of the day. I do a lot of cursing when that happens.