Being left-handed in high-level bowling almost always is a blessing or a curse: The sweet spot a lane man seeks that makes it fairly equitable in difficulty between the right and the left has never been smaller. That means one side or the other has an advantage — sometimes a large advantage. And in order to avoid a mutiny by the nearly 90 percent of players who are right-handed, a lane man has to be careful not to give the left side the advantage too often. The result is that being...