Excellent video demonstrating the importance of proper TW

I found out many years ago with my dad and his boat trailer that his is very real and applies to real world towing. He moved his boat back on the trailer by moving the winch back so he could lift the tongue by hand. All fine and dandy towing back and forth to the boat ramps. First trip on the interstate was interesting to say the least. We moved the winch back to it's original position and it towed straight with no sway.