He usually wasn't a pressure fighter. He mostly boxed behind the jab, circled, opened up with combos, and attacked when he hurt his opponent.
If Hopkin's trys anything before the fight, mentally frustrate Marvin Hagler would come into the fight like he did against hearns, but even more angry coz Hopkins really gets to you. Hopkins by a very very close UD. Hopkins was brilliant at capitalising on a mistake
He could play one when the situation called for it, but only resorted to using it as his primary style at the very end, due to his deteriorating physical ability. In his prime he was a smooth, controlled boxer/puncher who could go into finishing mode very well. Watch the video I posted before of his bout with Loucif Hamani, where he boxed and felt Hamani out in the first round before switching to skill in the second round the very second he got Hamani hurt. In his even younger days in the late 80's he was actually a bit of a cutie stylistically, definitely not what would be called a pressure fighter.