I think a young Tyson would beat Lyle but it wouldn't be easy for him. Lyle was a lot better then Mitch Green and Tillis who took Tyson the distance when he was young. I think if he met a test like Lyle instead he'd have had to go through and back and forth battle which would've been much tougher then his fights with Tillis and Green. Tyson at this point in his career didn't seem like he'd be stopped and if he had come up in a different era and been tested against Lyle I think he still would've won based on his aggression and skill but it would be close and likely over the distant. In his prime I think he gets Lyle out of there like he did to Frank Bruno eventually wearing him down and finishing him while his backs against the ropes. Frank Lyle is a good contender in any era but you could always expect him to fall short against the very best of each time.