My hook with vertical position fist is more powerful than the horizontal one and I feel my forearm and bicep muscles involved more in that punch. Maybe you feel differently because you haven't trained the vertical fist hook and your body isn't used to its specifics, that's why it doesn't generate that much power. All those Tyson iconic left hook knockouts have come from vertical fist position. Wrist and knuckle injuries at horizontal fist position hook come from hitting too often with your two weak knuckles and because in vertical fist position your arm is straighter. Straight punches and crosser are obviously much more powerful with horizontal fist, I agree with this. Same goes for uppercuts. But not hooks, at least not in the most cases.
I already said in my post the hook is the excpetion due to the action its thrown with. I use vertical postion for that too
In my opinion both techniques are correct, however when the palm is down the fighter can get an extra twist on the wrist which gives extra power. Also if you are having problems delivering palm down hooks then there may be a problem with your biomechanics of the shoulder girdle, and this may prevent you from having full flexibility of the arms and shoulder.
He was a professional boxer. So based on the advice here, I will forget the two handed block. I'm still baffled by this and why he seems to love this method so much. I will also start mixing up my hooks.
Check your deltoids for muscle damage, often observed as indentations of the deltoid when the arms are extended. It is my opinion that exercises such as, weight training, press ups and pad work damages and flatten the deltoids resulting in loss of power and dexterity. If you observe Carl Froch's left shoulder you will see indentation of the deltoid and this is the reason I believe why he carries his left hand low, it is not comfortable for him to hold it high due to deltoid damage.
The vertical fist is good for breaking through a guard to open your oppenent up. You see Pac and Lomachenko do it, it results in the oppenent squeezing their gloves together in reaction opening the opponent up for the hook.
According to fight science the vertical exist is more powerful here's why.https://m.youtube.com/watch?v=3dMJx4I7ivQ https://m.youtube.com/watch?v=1BUpqHUuRHs
The reason you can't punch how he wants you to his because your arms are not flexible enough to turn over your punches.
That drill is right but it doesn't sound like he is using it correctly. You rarely ever want to land a shot with vertical fist. I used to throw hooks with vertical, I ended up with wrist injuries and it creates a gap for a counter right. What he told you is a little bit more advanced about trying to sneak a 'cheap shot' in. Naturally, vertical felt easier to me at first. But it didn't work out in the long run. Unless you have huge ass gorilla arms, your legs should be putting you in position to hook around guard. TLDR: Combination of both. Sounds like your trainer isn't exactly Angelo Dundee and you come off as pretty new to this. Stick with it, learn what you can. Keep an eye out for a better gym/trainer.