Backtest Fitness Function

Hi,

Just wondering how the backtest fitness function is supposed to work using the GA testing?

If I set equity drawdown to minimize as number one, how does a test set with a higher equity drawdown get a bigger fitness fuction number, and hence come out on top?  Is there a way to do this to get the most profitable, with the least drawdown on equity.

Also if equity drawdown goes below 50%, does a trade get stopped out in the real world?  If so, how can I eliminate this from the GA population chosen as being fit?

Finally, how can I stop a test set with a final value of negative equity from being selected as 'fit'?

I have a feeling that I'm doing something wrong, as these results don't seem to relate to what I'm expecting the tester to do for me?

I will use brute force for now.

Cheers,

Martin.