The G7 system is very simple and has arguement to it . It is based on watching price action in relation to overimposed 100 & 200 Bollinger bands.
When the price penetrates one band and it indicates oversold or overbought then there is high probabilty of reversal . If the price has penetreted both Bands then one can argue greater probability is at hand .
Essentially then this is a counter trade strategy and is discretionary and therefore cant be backtested in the normal sense .
They use the Stochastic and the RSI to support oversold and reversal of price action .
Together with reading candlestick formation , this system can be profitable and I believe their claims of 200/250 pips pm are achievable and modest .
How ever one nees to apply some effort to "see" the trade at hand and pull the trigger and use the necessary disciplines to complete the trade.
This may be out of the ambit of a some members of the forum who expect to be spoonfed with the Holt Grail every day .
They trade using 1hr & 4hr charts