Yes, I found the usage odd. He equates "unpredictable" with "random", which is not how I have usually heard the term in strategic contexts. That means unpredict

Yes, I found the usage odd. He equates "unpredictable" with "random", which is not how I have usually heard the term in strategic contexts. That means unpredictable, even assuming perfect information. The usual meaning of "unpredictable" is more like the author's use of "secrecy", meaning "denying the ability for competitors to confidently predict the next move".