Agree totally Barny. I also eliminate all first uppers for the same reason. It's just a question of fitness. When it comes to systems, my personal preference is for between 2 and 5 runs from a spell.

Not saying I never back a horse first up or 2nd up, but for my systems, I utilize the 2-5 runs from spell rule.

Heres a very simple elimination rule: 4yo or 5yo's only.
I'd be surprised if that doesn't improve any system.