Weak Bid?
The normal range for a weak 2-bid is 6-10. But, after three passes, surely you wouldn’t open the bidding with 6 points (nor 7, 8, or 9). Really, the range for a 4th-seat weak two should be about 10-14.
After three passes, I’d be happy to open 2
with: K Q 10 9 6 5 
K 3 
9 8 
K J 5
This combines preemption with description. Of course, you can’t open this hand 2 in any other seat, because it is too strong. Three-level preempts in fourth seat also show close to opening-bid values.
[box]Do not open a weak preemptive hand in 4th seat![/box]
Pearson Points
The «book» rule on whether or not to open with a 1-level bid in 4th seat says to add your HCP to your number of spades. If the total is 15, open the bidding. If less than 15, pass it out. The theory is that it will be a partscore battle, and if your side doesn’t have enough of the high-ranking suit, you could easily lose the battle. So, you would pass out this hand: 4 K J 5 4 K J 8 7 K 9 8 7
But you would open this one: K Q 10 9 2 A J 4 8 7 6 5 3
Note that the second hand has one fewer high card points than the first.
[box]This rule is commonly called «Pearson Points»[/box]
Now, forget the Rule of 15 for deciding whether to open or pass out the deal in fourth seat. I prefer CRIFS- «Cohen’s Rule In Fourth Seat.» Any time it is borderline (like 10, 11, 12 HCP), evaluate your opponents!
Yes, I am serious. If you are playing against Jeff Meckstroth and Eric Rodwell (or the best pair at your local duplicate game), then pass it out. You will likely get a middlish score/result. Who needs to open and have to do battle with an expert pair who will fight hard for the partscore and play or defend well? Conversely, if you look up at your opponents and see Schlemiel and Schlimazel (the worst pair), then open the bidding. You can push them around in the auction and will get an extra trick or two in the play/defense. You rate to go plus–so don’t pass the board out.
Larry Cohen