I am always sceptical of Pelz. Especially his "figures" or "percentages". He claims to be scientific, but NEVER releases verifiable data. He was so darn wrong about his aluminum shafts in the 1980s that it is wise not to trust ANYTHING he says. But he is dangerous precisely because not everything he says is wrong. But I KNOW this much, if he gives a hard number like 83/17, it is a number he just pulled out of.....thin air.