I’m calling bull ****.
I don’t know whether this idea has been floating around or not. If it has, I haven’t seen it, and a quick Google search didn’t turn it up (although my Google proficiency may be lacking). But really that’s beside the point.
You’re exactly right in your response to him that he tried to pass this off as his own idea, when clearly it wasn’t. If in fact this was “not a unique idea,” as he said in his twitter response to you, then why didn’t he say that in his article? You know, something like, “An idea that’s been floating around the internet and which has been suggested to me by several readers would be to . . . .” And then explain that it's his opinion (as opposed to his unique idea) that it’s a good idea. Simple. Then everyone knows he’s not the originator of the idea; he’s merely advocating it. Instead he tried to claim it as his own idea without acknowledging that the idea’s already out there.
His smart *** twitter reply asking whether he should have disclosed that “some other people also agree with this idea on the internet” is also bull ****. “Agree with” implies that he came up with the idea and others agree with him, as opposed to the reality that others came up with the idea and he tried to pass it off as his own.
And I find it pretty damn suspicious that his “idea” was so close to yours - three permanent opponents and rotating the others (again, maybe this idea is already out there - if so he should have no problem proving that). Making small changes to the match-ups is what would be expected of someone trying to claim the idea as his own, so that means nothing.
Verdict: Bull ****. I agree with trying to get Spencer Hall or Deadspin on it.