I agree on limiting a person to a certain number of guesses between host updates or maybe quesses per day, perhaps 1 guess between updates, or 3-5 guesses per day. This will make puzzles run a little longer, but at the same time more people could be involved. When I did puzzles in Dog General, I could start the puzzle, then do the first update several hours later with only a few letter guesses. Most puzzles lasted over a day.