There is no way a concussion would slow you down physically in later fights... It doesn't damage that part of the brain 99.9...% of the time. I think that Winky had his number and so did Forrest... He much slower than when he fought Oscar the first time, and he had a plenty of trouble against Oscar's jab let alone WInky's. Some people say its the added weight I say he is just overrated... he had physical talent but he wasn't trained properly growing up and that ended up being his undoing.