I would refrain from using character names in your logline unless that name helps the audience understand the character. In this stage, it doesn't matter to us that he is named Mark. You're better off using descriptive words to tell us what he is like or what he does for a living. It might also help us understand why he must convince his ex to join if you tell us what her area of trivia expertise is. Otherwise it might all feel a bit... well, trivial.
My other suggestion is to be aware of this: http://www.youtube.com/watch?v=uykl2z_7N_0
I am not saying you are ripping it off, but you should be aware that it exist so as not to get too close to it.
Good luck!