Hi timsk,
Yes, I do agree that the amount you risk on each trade should depend on the overall strike rate and expectancy of your system. The 1% to 3% I quoted was applicable for my own strategy.
The best way to determine how much to risk on each trade is to first work out your strike rate, and then run a simulation to ascertain what your worst case losing streak scenario would be.
For example, let's say you have devised a strategy that has 60% winning trades. With this sort of strike rate, if you trade it long enough, you could easily have a run of 10 losing trades in a row. Now let's say you choose to risk 5% of your capital on each trade. If the worst case happens and you hit 10 losers in a row, you'll wipe 50% of your account. So now you ask yourself "could I handle this level of risk?" If the answer is no, then you may decide it's ok to risk 3%, in which case your 10 losers would wipe about one third off your account.
The amount you risk on each trade is ultimately determined by your own tolerance for risk. There are traders who could see half their account wiped out and still remain unphased, whilst there are others who start to get nervous when their account goes down by 15%.
You need to assess what you can stand, and from my experience this is different for everybody.
Thanks
Damian