[jay_shark]

You will need many games to determine your true ROI .
If you want to be within a one percent of your true ROI , you will need to play over a 1000 games .

From my experience and with talking to many other heads up specialists , winning over 70 % of your games playing 50 + is simply not attainable . That is , if you play enough games to be within reason of your true ROI , then it's not attainable .

Your goal is to win more than 60 % which in my opinion is pretty good . Surprisingly , my win rate playing limit hold em is better than nl , but I think this is because there are weaker limit hold em players than nl .