Many years ago, I experimented and designed profitable systems that used random entries; and stop-and-reverse entries/exits. The edge was in the loss, profit, and/or time stops.
I also ran a trading contest and entered a dummy (control) trader that traded based on the first digit of a state lottery pick-three daily draw. It outperformed all traders (several) for three months, and was freakishly profitable (on paper, of course) with low draw downs.
That said,
It is just as difficult to make a system that is wrong 80% of the time, as it is to make a system that is right 80% of the time. Think about it, they are one and the same.
Most losing systems are around 50% (i.e. random), imo. slippage, commissions, and what I call the percentage paradox is why reversing such a barely losing system, will not create a winning system.
I call the fact that losing 10% (or any percentage) will require winning more than that initial percentage (or increasing risked capital) to get back even, the percentage paradox.