Anti Percentage

The following hand came up today in the Nickell vs Welland match to decide who plays Fleischer for the second USA spot in the Bermuda Bowl. Others may prefer to write about doubled grand slams making with two top losers, or the correct way to bid a 0607 shape, however the more mundane but higher frequency hands like this one tend to interest me.

How much would you bid with the South hand opposite a weak notrump?

Below is the Meckstroth-Rodwell auction but South at both tables jumped to game after discovering four hearts in the North hand. My instinct was that inviting is enough so I decided to run a simulation. The simulation is based on North as declarer with a balanced 11-14 including 4 hearts. I chose North on the basis that you either play a weak NT or transfer responses to 1C. This probably improves the expected number of tricks a little.

Results are as follows:

HCP	Num Hands	Num Makes	%
11	11120	1696	15.25%
12	9720	2935	30.20%
13	8371	4342	51.87%
14	6784	4495	66.26%

This suggests that inviting is plenty, and opposite an 11-13 hand even pass is possibly correct, especially when you also take into account hands where eight tricks are the limit. Certainly non-vulnerable it is right to pass if partner has a maximum of 13 and just invite if his maximum is 14.

Dealer: N ♠ Q 10 3 Vul: N/S ♥ A 9 8 7 ♦ K 10 ♣ Q 8 7 5 ♠ A K 9 5 ♠ 7 6 4 ♥ 2 ♥ J 10 ♦ 8 7 6 5 3 ♦ Q J 9 4 ♣ 10 9 6 ♣ A K J 3 ♠ J 8 2 ♥ K Q 6 5 4 3 ♦ A 2 ♣ 4 2

W N E S 1♦ P 1♥ P 2♥ P 4♥ P P P