There are very few juveniles that have been to the Supreme, but they have performed pretty well given there have been so few. Hors La Loi, Binoculor......... I reckon you'd have backed Our Connor if he'd turned up in the Supreme with a 7ln allowance Maurice?
Probably not the best example to use, Maruco. By that, I mean that Our Conor was rated 150 (I had him on 148+p) but in the 2013 Supreme he would have been up against My Tent, rated 162, and Jezki, rated 154. He would still have won, in all probability, as my post-race mark for him was 168+ but the allowance wouldn't have played a part.
And I reckon any of them would have pissed up in the County if they been given a mark in the high 140's and then had the juvenile allowance taken off.
They probably would, because their ORs under-rated them but, again, the allowance wouldn't have played a part. It might even have prevented them from making the cut!
The juvenile allowance isn't 'taken off' in handicaps. (I know you know that, Maruco, but some people might misinterpret what you're writing.)
If two horses are rated 140, one a 5yo and one a 4yo, they might be 8lbs apart in the weights but the adjustment for the younger horse is only made to 11-6 so it's swings and roundabouts. Carrying less weight might tilt it in favour of the younger horse but the older horse might be better built to carry the higher weight so, again, swings and roundabouts.
The only thing that really matters is whether the rating is correct in the first place. If 140 truly reflects the 4yo's ability but the older is really a 145 horse there's only one I would be interested in backing, and it wouldn't be the 4yo!
Binocular was rated a pound higher than Captain Cee Bee (143 v 142) but couldn't beat him getting the 8lbs.
All that said you've got to have one that's good enough in the first place.
This is what matters.