Check me out. The top two knuckles of my left hand look as if I’d been worked over by the K.G.B. No, it’s more as if I’d been a catcher for the Hall of Fame pitcher Candy Cummings, the inventor of the curveball, who retired from the game in 1877. To put this another way, if I pointed that hand at you like a pistol and fired at your nose, the bullet would nail you in the left knee. Arthritis.