[mafribe]

A good proxy measure for the accuracy of BBdM's prediction would be how rich he got out of them. Given that BBdM's mostly concerned with macroscopic predictions about politics his claim [1] that he was right in 2/3 of his predictions, should have translated into immense wealth.

[1] Source: an old interview with him, maybe 10 years ago. I might be wildly misremembering here. Sorry, no better sources.

[ThrustVectoring]

Being correct in 2/3rds of predictions isn't enough to get rich - he could very well have gotten more things wrong than the conventional wisdom that earns $0 on average.