This is what I'll do.
Pre-Game:
If I'm hugely expected to win, I'll say I expect a win.
When my team are up against it, I use the bookies odds to determine this but I'll that they can win this.
If it's an even game that could go either way, I'll say nothing.
Half Time:
If we are winning, I'll say nothing.
If we are losing/drawing, but playing well, its we can win this.
If we are losing/drawing and playing badly, I'll go with disappointed/I want to see more from you.
Post-game:
Regardless of result, anyone below a 6 gets disappointed. Anyone above a 6 gets pleased. And anyone above an 8 gets delighted.