American sports fans are currently engrossed in the NCAA College Basketball Tournament, a.k.a. "March Madness." Even President Obama filled out a Tournament bracket with his projected winners in the single-elimination format. So far, if you picked the favorites to advance (as Obama mostly did), your bracket is doing nicely: only one team (Arizona) has pulled off a significant upset to get into the "Sweet Sixteen." In betting parlance, chalk has predominated in the Tournament. But how did chalk come to be the term associated with favored teams?

The history of chalk dates back to the old days of horse-racing, when bookmakers (or "bookies") would set the odds for each horse by writing them on a chalkboard at on-track gambling stations. The odds would change during the pre-race betting period depending on the amount wagered on each horse, so the bookmakers would often need to erase the posted odds and "chalk up" new ones before the beginning of the race.

The bookies at the track had to be skillful with the chalk to keep their slate-boards up to date with the latest odds. In the reporting on horse-racing around the turn of the twentieth century, sports journalists often referred to bookmakers with such flowery appellations as "the lively knights of the chalk and blackboard," or more simply, "the knights of the chalk." Chalk gradually came to stand for the bookmakers and their oddsmaking though the process of metonymy, defined by the Visual Thesaurus as "substituting the name of an attribute or feature for the name of the thing itself." For instance, a racing column in the October 15, 1903 Atlanta Constitution reported, "In the first race the chalk figures made it look like five entries and six favorites for the event."

Those who followed the odds put up by the bookmakers could thus stay loyal to the chalk and bet on the favored horses, or they could look for an entrant with long odds that could potentially bring in a bigger payoff. A quote from the April 27, 1907 Washington Post encapsulates the ambivalence that bettors felt toward the chalk of the bookies:

Chalk scares many a turf speculator. Let him pick a horse to win, and if he thinks he ought to be the favorite and the bookies lay a big price against him, nine times out of ten the horse won't be played.

Some wagerers weren't so chalk-wary and would simply bet on the horses with the lowest odds rather than looking for an upset. Such unadventurous souls came to be known as chalk players, as in this citation from the July 21, 1926 Chicago Tribune: "Sarko and Herby Coles made good for the chalk players, however, winning the third and sixth numbers and each victory was scored easily." A less flattering term for chalk players was chalk eaters, a label slung by that master of American sporting slang, Damon Runyon. In a 1937 short story, Runyon defined a chalk eater as "a character who always plays the short-priced favorites." The gambler in question was dubbed Nicely-Nicely, who would later appear as a character in the musical "Guys and Dolls," based on Runyon's stories.

Eventually the chalk metonym made its transition to other types of sports gambling. Betting pools for the NCAA Basketball Tournament have proved to be a significant breeding ground for chalk talk. At the beginning of the Tournament, when the teams are announced and the schedule is set, fans go about filling their brackets with the teams they expect to win in each round. In offices and bars around the country, informal pools are set up, with the most accurate predictor of the games' outcomes winning the big pot.

Betting on chalk (picking higher-seeded teams to beat lower-seeded teams) is a boring yet reliable method of filling out a bracket. Here's Tony Kornheiser in the Mar. 14, 1989 Washington Post: "Anyone can pick chalk, anyone can send No. 1 and No. 2 seeds into the Final Four." But chalk-ophiles always dread the so-called "bracket buster," the team that comes out of nowhere and wreaks havoc with the safe predictions. Of course, such unexpected "sleepers" or "Cinderella teams" are very often the most fun to watch.

(It goes without saying that the Visual Thesaurus does not condone or encourage any form of illegal gambling. Make sure your office pools are on the up-and-up, even if your office is the Oval Office!)