That is an interesting question. I suppose it's equivalent to the 'worst case' performance for binary search, which would be a relevant topic. Finding the optimal strategy in the case where the opponent _may_ be adversarial could be interesting. I don't imagine the odds improve compared to the base situation, but not sure
what if you, say, decided to make the bet that your opponent is adversarial and just did binary search, but restricted high, low and mid to snap to the nearest adversarial numbers when adjusting them?