his head movement needs to improve
Agreed.
The only time his head moved the other night was when he got hit

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Does indeed need to improve his footwork too, not to mention working on his balance which would go hand in hand.
Very top heavy with comparitively small calf muscles for such a well set fella, tremendous physique but needs to become more proportionate. All very doable though. Fury has small calf muscles too, but he carries less compact muscle up top.
Daft as it sounds for a big fighting man, the odd dance/ballet lesson would not go amiss.
Not enough emphasis on natural fluid movement in the heavy weight division, possibly because they are so big these days, but for me that's no excuse. Yoga would also help not only in terms of strength and balance but breathing and relaxation. He tenses up an awful lot. If he already does these things then he needs to do them more often.
The young Mike Tyson's early training with D'Amato involved lots of head movement to reduce the number and impact of blows on the way into mashing his bigger opponents. I remember seeing training clips of him avoiding a small swinging lead weight on a chain to improve his technique. Not sure how many ballet lesson's he took though

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Nothing wrong with a bigger fella moving out of the way and working his angles better on the way in too. Although Joshua caught up with him, Whyte did at least slip a lot of his punches and used a bit of ring craft to land his own. Joshua also tends to throw arm punches rather than using his whole frame. The power he currently generates does punish his opponents, but the power he COULD generate would be truly devastating.
Don't get me wrong, I think that Joshua has an enormous amount of potential and he does throw a decent selection of punches. It'd just be a shame if his potential was knocked out of his ears before he has a chance to show case exactly what I believe he is definitely capable of.