Changing the basic rules on small sample sizes may trade the worst thing you can do. Say you have placed 300 trades with your current rules. Although you have ups and downs, this has been a profitable strategy. Then let's say you lost 5 trades in a row, that can happen. Suddenly you change a rule that has withstood the test of hundreds of trades based on the size of the sample. Overreact to a small sample of trades can take you to a dangerous road.