Actually I think thats a good point. The statistics isn't just about the system behaviour its about our behaviour and how we would psychologically/emotionally react whilst trading the system. I think as far as the system stats is concerned if it consistently wins in the long run thats all that matters. But for us trading it, the other stats plays more of a role.
Rog, you jogged my memory about why I was including consecutive wins/loss. It was actually for my own psychological needs to 'feel' like the system is working. I remember sitting down over a year ago and telling myself that I needed a system that produced twice as many wins than loses and would show reasonably long consecutive wins with short consecutive losses. Just so that on a day to day basis I felt confident, even though I know that its just as likely (or maybe even more likely) that a system with fewer wins but high win/loss ratio would produce better results in the long term.
The consecutive winning days is exactly the same as the run-up stat (opposite to drawdown), which shows how much profit was made without a single losing day. Useless as far as a system is concerned really but purely an emotional support.
Maybe if the system is going to be traded mechanically it doesn't matter as much, but if it is manual and discretionary then it probably has more impact. Although having really good stats including long consecutive wins shows signs of a possibly highly robust efficient system
Fettered, I'm planning on using multi-system trading, several systems running that specialise on range and trend trading. I'm also using reasonably large portfolio's to balance out risk. Also using recent history optimisation with a dynamic look back period (takes a lot of processing time for that though). One of the reasons I'm concentrating on stats and which stats are the best is also because I'm planning on changing the optimiser to possibly work off statistics for the look back period instead of just profit. So you can tell the optimiser your wish list and it will produce parameter set ups that will match it as best as possible. Although, whats a more important stat than making the most amount of money?
Is there a profit expectancy/probability stat per trade? I remember it being discussed before?