You certainly can often do better than individual experts by averaging experts, but BDM's methods actually do add something.

To the extent that BDM predicts things like the Khomeini succession (and something about the Indian parliament, if I recall one of my political economy classes) in ways nobody else sees, including himself, it's worth understanding just how game theory allows unexpected or unintuitive results from completely basic inputs.

BDM's use of experts is confined to the inputs--a place where their judgments are more straightforward. It is rather easier to compare the relative power of two parliamentarians, for instance, than to predict the outcome of a multiparty election. Averaging experts' opinions on the latter may not improve forecasts much, and that's where BDM's innovations have been useful.

I should note too that he sometimes derives the model inputs himself.

I don't want to oversell his abilities, but he's doing pretty innovative work at the cutting edge of political economic theory.

That's how I first heard about him. I've been boosting those for a while.