29 for me in one annoyingly competitive group that keeps me on the toilet for hours.... but I've got several chats going on and the lesser players are the most fun.
As soon as it pops up "xxxx scored 9" I just score 10 then miss on purpose. As soon as they set another score, beat it by 1 again. It really annoys them if you do it almost immediately after the score pops up. You can ruin someone's day with little impact on your own that way as they try and beat you again and again.