That answer helps tremendously, I thought I was missing something. I have no substantive reason to put this notion forward, but I have intuitively determined that a horse running a 4 on the dirt would run a -7 on the turf, again, everything else being equal, breeding,distance,trip, etc. I had no way of determining if there was a rule of thumb so I guess I was streching. It was especially perplexing because I know the average turf coarse in the US is faster than dirt so you would expect that a turf number would be faster than a dirt number not slower. Just my insights after using your sheets extensively for many years. I mostly buy the sheets at the track so you probably don't realize how loyal a customer a truely am. I wish you had them at Monmouth in their off season because I have to drive 30 minutes each way, to freehold to buy them. Great product though or I wouldn't do it.