Only thing I suggest is to look at it like a paycheck. Figure every time you bet you earn something. Just because you went 3-0 tonight doesn't mean you should treat that like it will always be there right? So just figure a conservative guess at your edge, say 3-5% per base dollar wagered. Multiply your bets and that is what you can say you have theoretically earned. When that amount is big enough to justify stepping up and your results have been enough in line to also justify the move, then you should step up. Lots of people just base it on how much is in the bankroll at a given time, but if the amount went up due to a lucky run its best to be careful.