Self Esteem

I'ts been a busy weekend with parties for the kids followed by get togethers at friends homes wich last late into the night. It takes a toll, as getting up on Saturday morning for soccer is next to impossible. Alas, we have no choice and manage to get to the sports center for a miserable game which was lost by a landslide. The kids still have to be told how they played well and tried their best and as always followed by "better luck next week".
Are false paraises a good thing? I'm not so sure but am told that is the way to go so that we do not harm our children's self esteem. I'm always told to praise their posotive efforts and let them know how well they are doing. Do not reinforce their negative behaviors.
Truthfully, my son played terribly in his game. They didn't work as a team and were simply beaten because the opposing team played much better and were concentrating on the game. I start by telling him it was ok to loose and the usual shpeel about doing better next time...but....my tongue gets the better of me and I start to critisize. I try to do it in a constructive manner by explaining where he had made mistakes and how he could avoid doing the same thing next time. He took it quite well and hopefully will improve next week. Again, that will depend on his mood when he wakes up. Part of this weeks failure is because he didn't get enough sleep so I guess I take responsibility for that. It's difficult to avoid social commitments, especially when it involves close friends and family so the kids will just have to learn and adapt to the odd late night here and there.
Did I harm his self esteem? I don't think so ,because he reamined adamant that he played a good game and bad luck made them loose. A little over confidant perhaps, but better than lacking in self conficdance. His little brother seems to be learning from all this and should do ok for himself too. He believes he is the best player in his team. Ah, the wonders of children!