I would word it differently but I agree that finding that "positive expectation" is simply a very hard thing to do.
Agree completely. And then having the sense to make the necessary adjustments in order to maintain a "positive expectancy" under dynamic and evolving market conditions. In terms of "discipline"; well, do not underestimate the ability for certain human beings to butcher a perfectly reasonable trading system. If you take a very simple system that by all rights is 'mechanical'- say, a 5 period to 20 period MA Cross using 5 minute bars, the performance variance between 20 traders subjected to identical markets is wider than it ought to be... That five inches between the ears is quite the wild card variable.
it didn't take long for a worthy contender to arrive on the scene. the cold day in hell has arrived. let's rent this super freighter for $608 for u and your friends. http://www.elitetrader.com/vb/showthread.php?threadid=245536
If I'm ever at a garage sale and I see a picuture of Lyndon Johnson, I'm going to buy it and put it on my wall in my trading room to remind not to do with my system what he did to society. Don't take something that is good and try to make it great.
lol ... and I thought it would stand for decades. Never has a record with so much going for it fell so quickly. It would be as if DiMaggio's 56 game hitting streak was broken in June of the next season!!
retail pikers can distort the market for a few seconds. then some nervous big player takes the wrong course of action.