I can't understand why diversification across uncorrelated strategies should not work.
Suppose you have a rigged coin. 60% chance of heads and 40% chance of tails. Let's define "heads" as profit, and "tails" as loss. So by tossing this coin sooner or later you will be in profit (more heads than tails). It's just a matter of time (number of tries). The probability of being in profit after 20 tries is bigger than after 10 tries, right?
Coin tosses are independent. Let's say we toss a coin 20 times a day. Take the first 10 and label them "strategy A", then the second 10 and label them "strategy B". The results of these two strategies will be uncorrelated, i.e. the strategies are uncorrelated. Now if you played only one strategy (A or B), you would get to toss a coin 10 times a day instead of 20, and the probability of you ending the day in profit will be lower.
So how did that guy proved this does not work?
Suppose you have a rigged coin. 60% chance of heads and 40% chance of tails. Let's define "heads" as profit, and "tails" as loss. So by tossing this coin sooner or later you will be in profit (more heads than tails). It's just a matter of time (number of tries). The probability of being in profit after 20 tries is bigger than after 10 tries, right?
Coin tosses are independent. Let's say we toss a coin 20 times a day. Take the first 10 and label them "strategy A", then the second 10 and label them "strategy B". The results of these two strategies will be uncorrelated, i.e. the strategies are uncorrelated. Now if you played only one strategy (A or B), you would get to toss a coin 10 times a day instead of 20, and the probability of you ending the day in profit will be lower.
So how did that guy proved this does not work?