Went to Google and found a Ninth Circus (current appelation) Court opinion on the case, Leslie Cohen v. IRS from 1959, which contained the following:

During the years in question the petitioner, Lesly Cohen, operated the Kingston Club, a San Francisco card room. During the same period and using the same premises as his headquarters, Cohen operated as a so-called 'betting commissioner.’ The latter activity was in violation of both state and local law. Either as a part of this latter activity (as appellant contends) or as a separate venture in which appellant engaged in personal betting (as the Tax Court found), Cohen also received income from a San Francisco establishment known as the Film Row Club.
As betting commissioner, Cohen would obtain opposite parties to wagers on horse races and other sporting events. Normally he did not accept a wager as 'placed' until he had found some other individual to 'lay off' the other side of the same event. When Cohen was able to 'lay off' the entire amount of the bet, his profit or loss would not depend upon the outcome of the event. Instead, it would be a fixed percentage or 'commission' of the total wager. When able to do so, Cohen would lay off the bet with his own local customers. When this could not be accomplished, he would lay off or cover the bet with other betting commissioners.

Notice the the clowns only define the Film Row Club as an "establishment", whatever the heck that means. Same kind of drunken idiots that populate the current Ninth Circus. This is the most relevant reference, but the whole forked-tongued document can be read by going to www.google.com and entering "film row club" and reading the single result I found.