What is the minimum needed to invite opposite a 15-17 notrump at matchpoints? The notrump opener is an average declarer. In order to answer this question, I asked some of the country’s best players four questions. What is the lowest card that you would add to each suit of the following 12-card hand so that you would invite opposite a strong-notrump opener? What spade? What heart? Responder’s 12-card hand is 
A87
765
K432
87.
Some of our experts have given us some concepts to think about.
Grant Baze—“The parameters are shifted considerably given the condition of matchpoints, as opposed to imps or total points.
Matchpoint parameters uniquely include:
1. You never want to lose a hand in the bidding. This means you do not want to make a close decision that is the opposite of what the “field” is likely to do. If you are in the same contract as most of the field, you hope to win the board in the play. Often I have seen 1NT making three score the same as if you had bid 3NT and made three.
2. While 37.5% is the breakeven point for bidding a vulnerable game at imps, and about 45% is the breakeven point for bidding a non vulnerable game at IMPs, matchpoints requires at least a 50% chance to bid game unless you are sure the “field” is going to bid the game.
3. At IMPs, vulnerability might be the determining factor in the decision to voluntarily bid game, but at matchpoints the vulnerability factor is basically irrelevant.
4. 2NT down one at IMPs is annoying but not tragic; at matchpoints 2NT down one may be a disaster.
This simplifies the decision to raise 1NT with balanced hands at matchpoints. All balanced seven-counts pass, all balanced nine-counts raise, and the only decision is with a balanced eight-count. With eight HCPs in a balanced hand at matchpoints, good spot cards, honor concentration, and distribution are the most important factors in determining if you should raise 1NT. 4=3=3=3 eight-counts should be passed, unless you have magnificent spot cards and good honor concentration. 4=4=3=2 eight-counts are better playing hands, and additionally are influenced by the viability of a major suit game. With 4=4=3=2 distribution, you need to take a hard look at spot cards and honor concentration, particularly in the major in which you hope to find a fit. 5=3=3=2 hands are better playing hands, but the honor concentration in the five card suit is the paramount consideration.”
John Hurd—“I think eight HCPs… Click here to continue reading