Quote from m4a1:
for #2 i think it depends on how your trades usually work out. if your trades tend to go against you at first and then goes in your direction, what you're doing works great. but if most of the good trades go in your direction right away, then you will have small size on the great trades, and large size on the not so great trades.
I agree. It's up to you to work out probabilities of every trade you make. Probabilities will command reducing/increasing position size, it's common sense. If you ask Gary he does double positions when he feels confident of the outcome. It's like driving in bad weather conditions, will you drive 70MPH or would you reduce speed?