When I Cap the surface I totally throw out a race where I haven't seen a horse that has a work or a race over the surface. I also look for horses that have shown good form over turf or a consistant work pattern over the surface. I also believe that certain jocks (like DaHoss said) have a good grasp on the surface. They are learning that they cannot rush to the lead. I also think some trainers have a jump on certain other trainers when running their horse on the surface. There are some patterns beginning to develop but I am not sure if they will be constant or not.