chalk
n.— «Chalk: Years ago—before computers, if you can imagine—bets were recorded on a large chalkboard. The favorites would get the most checks and thus the most chalk, making picking the chalk the term for picking the favorite. This, however, is nothing to be proud of. No one brags about picking the winner when the chalk comes home—which happens about a third of the time.» —“The lingo” Star-Ledger (New Jersey) Aug. 4, 2005. (source: Double-Tongued Dictionary)
Further reading
Need a slang term that can replace just about any noun? Try chumpie. If you’re from Philadelphia, you may already know this handy placeholder word. And there’s Queens, Brooklyn, Staten Island, Manhattan, and … The Bronx — why do we add...
The expression to go chalk has to do with rankings in an athletic tournament and harks back to when seeded teams or players were listed on a chalkboard. To pick chalk means to choose one’s favorite competitor, and you can also speak of a chalk...