Risk/Reward in Athlete Expectations
I think that overly hyping expectations/outcome is a high-risk move. Let's pretend you're working with an athlete, and you tell them you know they can hit 9/9 and that XYZ numbers are for sure in the books. Or, you tell them you believe in them to win a specific competition, to nab a 750 pull, and so on: extrinsic accomplishments, essentially.
One last example is that you build momentum from an athlete continuing to hit PRs, and praise them for continuing to hit PRs. You set an expectation that they will continue to do so in the future.
I think this is a somewhat dangerous practice because athletes can get a HUGE boost in confidence if they meet the mark or continue rounds of successes, but experience an equally large drop in confidence/motivation if they miss the mark and feel they've let you down. I know loss aversion fits in here, I'm just not quite sure how.
Anyway, making it more about praising the athlete and their practice, their internal strides, lasting qualities and substantive changes has more bang for your buck in the long game.