Imagine you have polling that indicates you may take as many as 56 or 57 seats in the Senate.
Imagine you have tons of raw SIGINT showing you where, when, how, and by how much Ds are planning on trying to steal seats.
You know that in order to breeze through the next steps in the process, you need to secure a minimum of a 53-47 majority of solid ally votes.
You also want to allow the Ds to incriminate themselves as much as possible committing election fraud.
At this point, a prediction of 53-47 is VERY easy to make, without knowing the actual specifics of the end vote.