most breeders cup races (especially since they added races) or other g1's are not filled with good g1 horses imo
i think you can toss up to 1/2 the field plenty of times..over the yrs there have been plenty who looked and deserved to be 8-5 or less uncle mo as a 2yo ouija board at lone star high chapparal at ap dayjur at bel etc
whether they are bc races or a 5 claimer the question is do they deserve to be 8-5 ?
imo the higher the quality of horse the truer they run to form
i was once at old spk on a sat afternoon and a horse was 1 win out of 49 starts lifetime but was the green sheet best bet of the day.. a cheap claimer he had been beaten a nose in his last start 1 for 49 and people really bet him down to heavy chalk !