We began playing this game years ago , then I saw it posted as a 'math' game and I got to thinking about how much fun we had had over the years playing a similar game.
We did it as a bell-ringer to begin the class and students were not allowed to have the same opponent two days in a row so it kept things moving. It generally took up about 10 minutes a morning with a grand prize each week.
Since then I came up with other History games which became much more fun for my classes such as 9-Men Morris, Jeopardy, UNO, I have-You have, History/Mystery and others.
It is clear that there are teachers who just want to try something new in class to get the information across to their students. I have lots of them.
We have used these ideas for learning states, wars, presidents, historical figures, trivia, and just pre-holiday fill-ins.