Originally posted by jaan
cesko,
yes, good point. randomizing the initial short/long decision will cancel out the market trend real nicely, so the trades will be perfectly 50%-50% symmetrical (if we ignore the commissions that is). it's really easy to prove that.
- jaan
It still won't work.
Not that it matters one whit anyway.
What a pointless argument...
yes it would -- it's a simple mathematical fact. effectively, after applying the random short/long decision, each trade that would have been a winner has a 50% probability of ending up a loser, and each trade that would have been a loser has a 50% probability of ending up as a winner. hence, all trades will have a 50%/50% probability of ending up as winner/loser. QED.Originally posted by darkhorse
It still won't work
hehe, i can tell you're a discretionary trader, right? for us, system traders (i trade a 100% mechanical system with no discretion whatsoever), probabilities and expectancy are the only things that matter.What a pointless argument...
so what? if you toss a balanced coin 10 times, and happen to end up with 10 tails in a row, would you say that the probability of a tail for the balanced coin is 100%?Originally posted by I Missed Boat
Say you win on 70% of your sells (35) and only 6% of your buys (3), you would only have 38 wins, not including commission.
-- as previous posters have said, the probabilities can be surprisingly tricky (and surprisingly powerful, too).no, i'm a partner in a software house, and we trade a proprietary system that we have developed ourselves.By the way, what system trading do you use, a black box?
Originally posted by nitro
DH,
I know you feel that way, but, FWIW, jaan/cesko are making arguments as they would be made by Mathematicians (these arguments are elementary, but probability is notorious for non-intuituve results.) They are exploring boundary conditions, etc., and working their way from there. I agree with you that they won't get anywhere, but it does not render the mathematics "pointless."
BTW, I thought all swingtraders were morons (ay ay yai, the heat I will get) until I read the way you approach it. Very elegant, I will think on it further...
nitro

i can see the discussion taking the "discretionary vs. system" path again, that has been done numerous times here on ET, so let me give you a summary of the argument that will follow:Originally posted by darkhorse
You can't apply textbook math to a chaotic environment, there are so many hidden variables and textures that the number crunching is usually drowned out by any number of a hundred hidden factors.
Originally posted by jaan
i can see the discussion taking the "discretionary vs. system" path again, that has been done numerous times here on ET, so let me give you a summary of the argument that will follow: