i think berto will KO brook by the 6th round jennings was having sucess against brook before the cut was stopped on a cut,
It's hard to say because Brook is still unproven. You'd have to go with Berto because he's actually been tested whereas Brook hasn't. Of course, every now and then you get fighters who are untested because they're excellent and could move up to world level with ease but I'm not sure if Brook is one of them.
Unfortunately this fight could entirely depend on where you stage the contest. In the UK Brook would win.. the US Berto. In my opinion
Kell Brook is a KO waiting to happen, a past his prime Cotto coming back from a brutal beating from Margarito he destroyed Jennings in 5 while a young/hungry prime Kell Brook beat Jennings because of a cut in 5.