Sorry to drum up a dead thread, but I think this TP ratio thing is inherently flawed. As Bob alluded to above, if this system was implemented to award good posts, it only partially gets it right.
Why do I say this? Because I recently noticed the TP ratios of two posters, "Who" and "BBallTim". Both of these guys are outstanding posters (although I don't agree with either all of the time) and they've got ratios below 20:1. That, to me, is just not right.
One thing I'd suggest to everybody is that we don't just reward TPs when somebody makes us laugh, or when they give us one. I think it's also important to reward those who are helpful, and most importantly, those who consistently post at a high level. The aforementioned two posters, plus countless others, fall into that group.
(Sorry to drudge up an inactive post; I saw BBallTim's ratio and it bugged me a bit.)