Sometimes Does giving to much Credit to one fighter,give leverage to the other?

For instance.Everybody is betting the farm that Floyd will beat Ortiz.Now maybe i shouldn't use this fight as an example.But say Last nights fights and many others this year alone.have been so wrong on the calls.And defeated fighters lost their zeros. Is it feasible that too much bragging on a certain fighter can be hazardous to his health and his record? In the ring i mean.Not many men like hearing the odds are definitely against them.It seems to bring everything he has out. And he fights and wins for the pleasure of you being wrong. That happens a lot.What do you think? Thanks for your contribution.