Good analogy. I'd say the efficient markets hypothesis would be better interpreted as "you cannot deterministically identify an inefficiency", i.e. you're alway

Good analogy. I'd say the efficient markets hypothesis would be better interpreted as "you cannot deterministically identify an inefficiency", i.e. you're always assuming some amount of risk with any trade. You could probably make a similar case for improvements more abstractly - you cannot be perfectly confident a priori that something will be net value additive over the previous configuration.