You are getting hot here. Did you know that very few traders know how to find "an indication of a higher probability". Most think in terms of MY edge or HIS/HER edge while there is nothing of that nature. There are only those situations where price is biased and will favor one direction. How you exploit these events is another matter. How you spot them is another too.
'An edge is nothing more than an indication of a higher probability of one thing happening over another.'
That reminds me of something Douglas said in Trading in the Zone.
It may be semantics but I disagree. That is not an 'edge' as we are discussing. It may well be that there is a higher probability of one thing happening over another thing at some point in time - but for us to have an edge we need to be able to identify those moments and use that to our favour. If we can do that consistently over a series of trades then we have an edge.
I sometimes trade with other traders using a sharing communication tool and many times two traders can trade in opposite direction as they don't follow the same rational and what i find fascinating is that both can win. Not the same amount but both can be profitable for this given trade. You summed up very well.