Ok. Question for systems guys: (bear with my trouble in communicating the idea): Lets say you develop a system, that relies on, a certain theory you have (dont we all). When the system recognizes a signal, to buy or sell, at that point, nothing is done. Instead, you rely on a constant value AWAY from the generated signal point to enter the market. Example: 1146 is the signal generated. BUT, nothing is done until price reaches, lets say, 2 points up or down (1148, buy, or sell, AND 1144 buy, or sell). Fine. The system backtests very well, without any fitting - you just happen to like how 2 points works (the results are nice). BUT, adjust that 2 points - play with that constant value, and the system falls apart. What would you make of this, and how to determine if this is / is not just a random number which happens to backtest well over 10 years data (nothing spectacular, just well?) Finally, would you trust it to trade it? Thanks.