Linda,
For what it’s worth, “rub of the green” may no longer be in the Rules but it’s still in the language with a very relevant meaning. Rub of the green means the influence of the grain.
When Hamlet says “Ay, there’s the rub” he is making a metaphoric reference to the way a ball (he probably meant a lawn-bowling ball) which had been rolling true may be deflected by the grain and “turn awry...”
Thanks so much for your excellent and entertaining information!
Lou from Sarasota, Florida
