I don't think you can ever do your best. Doing your best is a process of trying to do your best.

All you can do is to do your best.

Doing your best means never stop trying.

You are doing your best only when you are trying to improve what you are doing

I've always tried to do my best on the ball field. I can't do any more than that. I always try to give one hundred percent; and if my team loses, I come back and give one hundred percent the next day.

If you try to do your best there is no failure.