To be technical, it doesn't matter which lead you're on *going to the fence*; it matters very much what lead you're on when you go around the turn.
I have never, ever heard of a recommendation to ask for a change three strides after a jump, though techincally, any change that occurs after the fence and before you change bend as you approach the rail is correct.
If you are judging an unrated local schooling or green class, particulary if the entries are light, the judge has to exercise some discretion in pinning. If NO ONE in the class gets 8 spots and correct leads from a steady relaxed pace jumping in good form, the judge has some decisions to make - pin a horse with simple changes who jumps in tidy good form or pin one that didn't make the striding but that landed on the correct leads?
Finally, if you really want to know what judges are looking for, I *highly* recommend going the the USEF website and downloading the rule book. It's free, you don't even have to be a member. That resource, and Anna-Jane White Mullen's book, should give you the definitive answers.
ETA: Thank you, upnover. I think judging clinics, where you review score cards and explain judges notation and scoring, are a wonderful learning resource. You're right, frequently the judges aren't looking at what the riders think they're looking at.
Last edited by maura; 04-04-2011 at 06:11 PM.