{adv. phr.} In accordance with one's specialty or predilection. * /This kind of preclassical music is right up Bill's alley; after all, he wrote his Ph.D. on Bach./
{adj. phr.}, {slang} Suited to your tastes and abilities; what you like or like to do. * /Baseball is right down Jim's alley./ Compare: CUP OF TEA.
See: DOWN ONE'S ALLEY.