Although it is unknown to me who first developed the bridge system for "breaking out" keno tickets, it was a very useful, and as a professional tool, somewhat semi-secret method used by keno checkers over the years.
In the years before computerization of keno, the tickets had to be manually checked, and in the case of even moderately complicated tickets the checker had to be mathematically adept.
At it’s simplest the bridge system will let us verify the ways on a ticket. Suppose that we are presented with a ticket that has nine spots, grouped in three deuces and three kings, 2-2-2-1-1-1. To use the bridge system, we must split the ticket into two slices, so in this case we’ll put the deuces in one slice and the kings in the other: 2-2-2 and 1-1-1. Now we know from our vast experience that three deuces produce a one-way 6, a three-way 4, and a three-way two, so we’ll write this across the top of a page. At the same time, we know that three kings produce a one-way 3, three-way two, and three-way one. So we put these results in a column to the right of the table we’re constructing