I think that tall guy doing peek a boo is just wasting a times, his head still get exposed, and it still easy to get hit if he doing in boxing, his head always leaning back whenever he evade a punch, and he doing 'out boxing' with 'in boxing' style, he not doing it exactly what it's mean to be, its like very skinny dude doing sumo, you can do that as daily routine, but you can never go anywhere in pro. And peek a boo is effective if it get used by short guy. he better using other style that suit his heights and reach, because as tall guy he doing more better as out boxer and using his range as advantages in fight, and there's a lot of deadly style for out boxer that he can choose. Just because mike tyson doing good with it, doesn't mean everyone can do same as him, there's a reason why no champion in any division using full peek a boo style until today, every champions know what their capabilities, and they using it as effective as possible and neglected their ego.