# Can't quantum teleportation be superluminal some percentage of times?

This is really a subtle point. You are right that in 25% of the cases, Bob will randomly chose the "correct" measurement basis and thus get the correct value.

However, there is **no way** for Bob to know when he has actually chosen the right basis and when he has chosen the wrong basis, so his measurement outcome does not contain more information that a random coin-toss.

It is only when the information from Alice (regarding which basis to measure in) has reached him, that he can make use of his earlier (75% erroneous) measurements.

It is in this sence that information cannot propagate faster than the speed of light.

If you are happy with Bob being right only in some percentage of the cases, there is a much easier protocol which does not even require entanglement: Just let Bob guess Alice's bits. He will be right in 50% of the cases.

Note that once the probability to guess the right result is *above* 50%, communication is possible, e.g. by doing majority voting. In fact, the same is true if Bob gets the correct result with *below* 50% probability: In that case, he just has to flip every bit, and he will have the correct result with >50% probability.

So regardless of the protocol, what Bob obtains must always be correct with exactly 50% probability, i.e., random.