The Week 20 sleeper slate centers on four hitters whose current hot runs threaten to outpace their familiar labels: Kerry Carpenter, Andrew Vaughn, Yainer Diaz, and Luke Keaschall. The analysis weighs luck against expected stats (xwOBA, xwOBAcon, BABIP) to separate real upside from daylight-dreams. Carpenter’s surge comes with air-ball tendencies and a career-low walk rate that threatens negative regression, but his elevated hard-hit and barrel metrics hint at sustainment above league-average. Vaughn’s move to Milwaukee has sparked a potential positive regression arc, supported by a rising xwOBA, strong hard-hit rates, and favorable four-seamer/slider matchups. Diaz shows clear signs of positive regression as his xwOBA sits comfortably behind a still-respectable wOBA, with top-pitch threats offering a solid floor. Keaschall, the late-season call-up, has flashed elite numbers in a tiny sample; his sky-high BABIP and rare strikeout mark are impressive but unsustainable, demanding careful roster handling. Collectively, these four offer a mix of proven timing (Vaughn) and breakout risk (Keaschall) that fantasy managers should weigh against playoff schedules and league settings.