Snooker/one pocket
I have taught many good snooker players how to play one pocket. After they get the concept of driving a ball to the rail , and shooting bank shots ("doubles" to them ), many of them started to play tougher and most of them liked the game. Most top snooker players already play excellent safeties.
I was playing Neil Robertson, the Australian snooker player, and he was the "smartest" learning player I have ever seen. After playing a rack, I would show him better ways to play some of the previous shots, He would "Never" make the same mistake again!
Neil just won a major UK snooker tournament this season.