Result of my trading system backtest using metastock

here is the result of my trading system i am backtesting
what i do is run the system onto every security and get the % gain after my system went through them.
it's done in a bear to bull market from 1 Jan 2000 to 27 Apr 2006
after that i deleted all untraded stocks to the stock count seen here. My country has about 780 securities
comments please.

Winnings:
Average percent gain 23.39%
Standard Dev 24.18%

Total count 105



Losings:
Average percent gain -6.83%
Standard Dev 5.59%

Total count 87

Summary
Aveage percent gain 8.28%
Average Standard Dev 14.8830734
Total Count 192

Win/Lost count ratio 1.206896552
Percent gain/lost ratio 342.62%



* at first glance, the reward/risk(Percent gain/lost ratio) ratio looks good. i think the Standard Dev of the winnings is insanely high! that the one biggest thing i am uncomfortable with. doesnt look like the average profit of 23.39% is a real profit. Can someone with statical knowledge help me with it?

* are there any other considerations?

Hi wahkao

You may want to break up your test period into segments (i.e. 2000-01, 2002-03, 2004-05, etc. or smaller).

That way you can check whether the large standard deviation is an inherent feature of the trading system or the result of a bad period of trades (i.e. a particular market scenario).

If there are periods where the system is doing particularly badly, then at least you can find out what's causing the poor performance. Ideally you want the system to perform reasonably well over all market scenarios.

Regards

Craig