text:  Rock critic Ken Tucker has noticed that several significant albums are marking their 50th anniversary, and he's decided to devote a summer series to celebrating a wide variety of them. First up is Steely Dan's Pretzel Logic. Released in 1974, the band's third album yielded a big hit single, Ricky Don't Lose That Number. For reasons he's about to explain, Ken thinks Pretzel Logic is Steely Dan's best album.