Why Large Winning percentages are a bad measure for trading systems
In summary, each investor must look at himself in the mirror and ask what is more important – being right or making money? If profit is the ultimate goal and not pumping the ego, then understand that a smaller losing percentage is not only OK, it often is necessary for success.
http://www.sfomag.com/homefeaturedetail.asp?ID=-170744115&MonthNameID=August&YearID=2005
Scaling into a loosing position Scaling out of trades - by TaylorTree