I think the estimated win % makes the game too easy.
My suggestion is that this is either (1) removed completely, or (2) different estimations are given by different media organizations, promoters or characters in the game. The player can then see different estimations (this would need to include lots of bias and subjectivity). (3) Alternatively it could be an estimation from the trainer - the accuracy could be based on their experience and attributes (this also risks making it too easy). (4) Or maybe it could be replaced with a fan poll result - reflecting the support the boxer has or public desire for the fighter to lose.
As it currently stands, the estimation provided doesn’t always predict the result - but I have found it is a good guide generally and makes the game too easy. I’d also say it is currently ambiguous how it is calculated or whose estimation it is.