If over time, your forecasts predictably change, then you can be arbitraged.
If e.g. I know that you'll have a probability below 40% at some point in the future, and I know you'll have a number above 41% at some point in the future, then it's trivial to create a strategy over time that is guaranteed to make money.
Taleb's claim, as I understand it, is that Silver is incorporating random noise into his model and so will exhibit such predictably swings, which enables arbitrage.
If e.g. I know that you'll have a probability below 40% at some point in the future, and I know you'll have a number above 41% at some point in the future, then it's trivial to create a strategy over time that is guaranteed to make money.
Taleb's claim, as I understand it, is that Silver is incorporating random noise into his model and so will exhibit such predictably swings, which enables arbitrage.