There is an old golden handicapping rule about never backing 3 yr. olds until November and I generally don't back them until Feb. or March in the new year and concentrate on the 4 and 5yr. olds in '4yr. old and up' races until then. I like to have a reasonable bit of form to work with, not 'potential'.

Also with SR, by the time hoses have had 10 to 15 starts. their SR is set in concrete for the rest of their career and it doesn't matter a zip if they drop in grade trying to win as they get older, they still run the same SR.

Systems that have the rule 'must have won last start' in them are full of peril when applied to runners with less than 25% SR. A horse with a 10% win SR who has just won, has Buckley's chance of winning it's next start. I recently backed one that [miraculously] won it's last start by 7 lengths and was facing a similar field strength. It's still trying to find it's way home I think.