Saddlecloth, I've been making my own numbers at a couple tracks for a number of years and find myself somewhere in the middle of this Ragozin /TG debate. Aside from weather/track condition changes Beyer & JB are right, there are days when the variant will change. An extreme example of this usually happens at Suffolk Downs on the day they run the MassCap and Mosely Sprint. There is always a turf race preceding both these races, I’m there and I can tell you their track maintenance people use the extra time frantically working that track over to try and produce impressive times if the track appears to be playing slow. On the other side of the coin I do think there are days when you can tie sprint & route races together.