I don't understand how Chuck Hayes can defend at all at 6'6". At least if we get him, I'll learn something.
Hayes has a freakish combination of (1) quickness, agility, co-ordination, balance and overall mobility (2) physical strength and a low center of gravity (3) stamina.
He lacks explosiveness quickness + leaping ability + length.
When Jeff Van Gundy was the coach of the Houston Rockets, he used to say that Chuck Hayes was the most versatile defender on the Rockets.
That he was one of two players in the league, the other being Ben Wallace, who had the quickness/agility to defend guards + the physical strength/size to defend big men in the post. I think JVG also used this same point to compare Hayes to Rodman (defensive versatility, athletic gifts).
The Rockets did drills where they'd pressure the ball full-court and several of their comments gave glowing reports about tough a defender Hayes was to bring the ball up. One-on-one. Hayes pressuring those little 6 foot lightening quick guards.
That is how athletic Chuck Hayes.