First session of 2007 and some BR management

In my first 2007 session I had a terrible start.
Lost $500 within 10 minutes. The first pot was wit AKs against KK pre-flop all-in.
I knew this player was verry agressive and so I called his all-in after my 4-bet,
this time he had a hand. The second big pot was with QQ pre-flop all-in against AK.
Again against a very aggressive player who pushed all-in after my 4-bet and with A and K on the flop my queens were no good.
And the last one (50BB) was with KK vs AA which went all-in on the flop.

After that I made a huge comeback and ended the session up $1100 in about 2200 hands.
Biggest pot ($700) was one were I had AA and my opponent AK on a A high flop.
I also had a AA vs KK again but this time in my advantage. Overall I was pretty happy with my game although I noticed that there are some tough players on Stars. I tend to have the most problems with the 22/20/6 type of players. When they enter a pot it's almost always with a (re) raise, they probably are re-raising almost any pair on the button, which is very tough to play against, especially OOP.

Bankroll management and winrate

Another topic I was thinking about lately was BR management in corresponce with your winrate.I read a lot of forums and then it's very common to hear players say "I'm a 6 PTBB/100 winner". Most of the time those players, played about 50,000 hands and they think the winrate they had during that stretch of hands is 'their winrate'. In fact, when you've been winning 6 PTBB/100 over 50,000 hands you're longterm winrate is with 99% confidence between 1,38 and 10,62!
So the only thing you can conclude is that your at least a winner, but that's about it. Another example: you can tell with 99% confidence that you're winning between 3 and 4 PTBB/100 when you have a winrate of 3,5 PTBB/100 over 4,5 million hands!!

What has this to do with bankrollmanagement? You always hear that you need at least 20 buy-ins so you have little risk of going broke. But to get this to work you at least need to be a winner, otherwise a 100 buy-in BR is not even enough offcourse. But when can you say that you're a winner?? As told earlier it takes 50,000 hands of 6PTBB/100 winning to be sure you're a winner AT THAT LEVEL, but it takes 100,000 hands of 3,5 PTBB/100 winning to be 99% sure.
Also a winner at NL50 doesn't mean that you're a winner a NL100. Even a winning player over the past year, might be a loser this year because this year because of the much tougher games....

So a sufficient bankroll might not be the reason to move up, for me it's time to move up when I have shown over enough hands that I'm a more then normal winner (3+ PTBB/100) at a level. Yes this might take me 100,000 hands per level, but at least gives me the confidence (99%) that I'm a winner at that level.

ps: Calculations have been done with StDev of 40 (my Stdev), but this is somewhat on low side (some people I heard of had one of 60). You can look your StDev up in Pokertracker BTW.