Hello Haliffa,
Actually the complete backtest is indeed for the whole backtested period. I will give you an example:
Let’s have a profit factor of 1.2 for the complete backtest. This does not mean that the profit factor in the In Sample or the Out of Sample will be above 1.2. Could be less, could be more. When you place for both and the whole period, then you will have your equity line smoother and at the same time, the Profit Factor will be above 1.2 for all.