Weight in front of the hands, induces casting and if the weight is heavy enough, it will trigger the brain to activate slow twitch muscles.  This will induce inconsistency throughout the swing path, slow down swing mechanics, and reduce ball travel.  This has been proven through objective research and science for all sports that use sticks, clubs, rackets, etc. intended to strike an object. The science relates to the moment of inertia and how counter weighting leads the butt end of the device to the target being struck.  The effects, hands come through faster, the shaft follows and aligns to the optimal slot of the ball path, and speed increases generating greater power.  Also, swinging with counterweights triggers and/or maintains fast twitch muscles. For golfers specifically, the butt end leads to the ball, keeping the hands low and fast through the down swing, prevents the butt end from raising prematurely, and pulls the hands out and away throughout the follow through. Finally, when more efficient proper swing mechanics are experienced and recognized, they quickly map to one’s mental muscle memory.