Because his power is not that good Looked fantastic on the way up spanking puddings but once he moved up a level or two the knock outs/stoppages dried up No coincidence
He`s a bad finisher and AJ proved Parker doesn`t have his level of power by flooring Ruiz despite going on to display a weaker chin in that same fight.
His power looked good at a lower level but once he was facing world class comp it hasn't impressed as much. That's partly due to the fact he doesn't hit as hard as people hoped and partly at the higher level he can't land in combination like he used too. He'd hit guys and they'd go into the shell allowing him to keep throwing but at top level these guys throw back and Parker after throwing is a sitting duck and so he's hesitant to throw because he usually eats a counter.
When he is in with a big puncher or someone he respects he doesn’t sit down on his punches. He punches softly and quickly steps out of range. You could see that as far back as the Ruiz Jr fight. That he won just by one round. He has gone backwards since that fight and proven he doesn’t have the determination and fighting heart to be an elite HW.
scientifically he should have enough power to KO these guys because at 240 pounds and with his hand speed/athleticism force = mass x acceleration. Weird.
Probably because he's not as tall as he claims and is quite fat. That means he's most likely a natural cruiser. Maybe he doesn't get the same PEDs that Tua and that generation got.
Parker seriously lacks punching power and aggression. It's bizarre how cautious he is considering that he has fast hands, a good engine and a solid chin. He's happy to go the distance so he can squeak out a gift decision. After his last fight he said he wouldn't have complained if he'd not got it! Guys Parker went the 12 round distance with in the last 5.5 years: AJ, Whyte, Ruiz, Chisora, Takam, young Hughie, Fa, Cojanu(!) Guys on that list who Parker knocked down: an exhausted Whyte in the 12th round. Half of those guys had been stopped: Whyte by AJ, Chisora by Haye, Fury and Whyte, Takam by Povetkin and Cojanu by Donovan Dennis. All of those barring Chisora have also been stopped since, as has AJ. Of the 5 no hopers Parker stopped over this period, all had been stopped before: Haumono by Kevin Johnson, Dimitrenko by Pulev, Flores by Charles Martin, Leapai by Baden Oui, Kevin Johnson and Wlad and Shawndell Winters by Brian Howard. Maybe Chisora is finally shopworn and aged enough for Parker to stop him in the rematch but I wouldn't hold my breath lol. Parker is an absolute pudding.