First I will say, You gotta give me credit for admitting that I do that. Not wrap my thumb around the bar. I really can`t tell you why I don`t, but I just never did.
I don`t use much weight, so it`s not really that big of a deal.
Now for strike 2, I bench with an almost elbows out (BB) style, So there`s not much of a front to back movement. More like up and down.
I do NOT open my hands like that dude, but if I did, the weight would still not move around. For those who have tried with a thumbless grip know what I`m talking about. You really do have to do it to know that the bar WILL NOT FALL OFF YOUR HANDS. It has NEVER done that with me.
Hey, at least after the insults, I still got balls to admit it. lol