"The Sure Thing" is not one of my favorite episodes of "Racket Busters" because it's so very, very familiar. I've seen it on some other old-time TV shows (such as "Dragnet") and it's a large part of the plot in the Oscar-winning film "The Sting".
A 'nice lady' introduces a sucker, Mr. Crowley, to someone who claims that he works for a company like Western Union. This employee claims that he can get the results for the horse races BEFORE the bookies do. Crowley is greedy and thinks he's convinced the guy to call him first with the results so they can make a cleanup. Naturally, the first time Crowley tries this, he wins--because they're setting hip up for a HUGE payoff!
This one is interesting but as I mentioned, way too familiar.