I'm a natural born lefty....and i play golf righty.
Mainly because i played baseball for the first half of my life and i was taught to bat righty instead of lefty to begin with and i can tell you first hand that we are both at a slight disadvantage.
It isn't because TGM is a "right hand dominated stroke" because IT IS NOT! It is just simply we are stronger on the other side of the body
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Case in point:
During baseball i was never a big guy ever, very small and very fast. But i could throw a high 70s fast ball (for a 14 year old kid) and usually played the out field and had a pretty damn good arm.
Hitting though, I didn't have a lot of power at all. I hit for average and never had enough power to hit a towering drive.
Later on when my brother forced me to learn to switch hit and hit lefty BOY WAS I SORRY. I wished i had learned lefty to begin with because even though it felt like some contorted move when i swung the bat, when i made contact
BOOOOOOOOOOOOOOOOOOOOOM!!!!!!!!!!!!!!!!!!!!
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So i'd say we are just at a small disadvantage....however i still swing in the 108-110mph range with a driver which is still pretty damn good.
Also, whether you know it or not, PHIL MICKELSON swings in the 120mph range and he is a NATURAL RIGHTY who PLAYS LEFTY.
Hope that helped somewhat