Since the
thread itself didn't specify, I'm presuming that it's only a one guess only deal.
We've dealt with both sets of rules in the past, so there's no real way to judge the intentions this time based on previous games.
Edit: But, seeing as Chadley is an honorable guy, he'll probably honor whoever gets the first guess, regardless of how many times they've guessed in the
thread, solely because the rules weren't specified directly in today's
thread. There'll be drama otherwise. So, it's probably safe to say that you can guess as many times as you want and as often as you want.