the solidus , i used it for ages, but it needed to be computerized ideally for speed of calcs, it was hit and miss but with some good winners, one great day was at York where it picked (worked out) a horse called ICE and it won at something like 16 or20-1, think in the end i concentrated on 1mile/8 furlong races, but I also think the Speed ratings didn't help in the weekender, sure something changed, and if you had an exceptionally fast time it seemed to knock others out of kilter,
I am sure some one did this on a web site and claimed good results