Originally posted on 12/18/2018:
Strongly agree with this (at least in any liquid market). You can prove it with sufficient betting history too: your edge estimates have errors, and as the edge increases, typically those will become asymmetrical - ie the real edge will be well below your estimate.
There's a good logical explanation: very large edges represent where the market knows something your model doesn't.
For anyone using Kelly this all becomes rather important :-)