I'd say better than 50% chance that the delay increases. But the phrase would be unambiguous if it were called an "exponentially increasing back off algorithm".
This is unnecessarily pedantic. An exponential back off algorithm has a 100% chance of increasing the delay, that's the whole point. Nowhere other than pure mathematics would I see the phrase "exponentially" and even consider a <1 exponent.
My probability was for hearing the phrase "exponential back off algorithm" without knowing anything about the algorithm. I don't work in that field and had never heard of the term before the earlier post.
Experience suggests that most of the time when people say exponentially they mean an exponent greater than 1, but I have been surprised by what people have meant before so I personally wouldn't say that probability is greater than 90%. That's what I meant in more detail.
