Table for 1NT vs 1 of a Major

Should you open 1 of a major or 1NT with a five card major and 15 to 17 HCP? That is the question that I am seeking an answer to.

Skip to the table!

After looking at some hands I realized that opening 1♠ was a little bit different from opening up 1♥ so I split them into two different groups:
1♠ vs 1NT
1♥ vs 1NT

How will I analyze this?

I am starting by looking at 64 random hands with 15 to 17 HCP and five ♠ and 3-2-2 distribution in the other suits. I generated the hands by using this website: http://playbridge.com/

You can specify HCP and also number of cards in the suits among other things.

So I set the hand generator to create 64 hands (the most you can do) with five ♠, two or three ♥, two or three ♦, two or three ♣ and 15 to 17 HCP.

Double Dummy?

Obviously I won't know what will happen at the table. Contracts that should go down sometimes make. Contracts that should make sometimes go down. But I have to assume best play for results. Therefore the results I am looking are Double Dummy results. Double Dummy results can be a little tricky. Double Dummy results assume that you know what ALL four hands are and play accordingly. We don't get to do that. I will look at some to make sure the Double Dummy forecast is somewhat accurate though. If you have to drop a singleton King offside to make the contract I assume you will go down.

On the hands that I am unsure of I give to my students. If they can make the contract I assume that you will. If they can defeat a contract I assume that you will.

64 Hands?

Will 64 Hands give a definitive answer?

No. But it's a start. Eventually I hope to add more and more hands. But depending on how many hands go one way it might be good enough for me. If on all 64 hands it is better to open 1♠ then I might be convinced. If it is better to open 1♠ on 39 of them I will want to investigate a bit more.

How will Opener show their values if they open 1♠?

Good question. I need to be consistent.

If they have 15 or 16 HCP I will just have them "Pass" if Responder responds 1NT. They might miss a few games if Responder has 9 or 10 HCP but they will also stay low if Responder has 6 to 8 HCP. This is not ideal but it is the easiest thing to do. This is where the people playing a forcing 1NT bid might get to a better spot. You could rebid a lower ranking three card suit but I'm going to assume you will NOT do that. That's a little complicated for my audience.

I will have them playing Standard American -- not 2/1 Game Forcing. Again a little complicated for my audience.

If they can open 1NT and are able to then come back in later to bid their suit I will assume they will do so if they have a GOOD suit. But I won't assume they will bid if they have a bad suit.

If they have 17 HCP I will just have them invite game with 2NT if Responder responds 1NT. They might get a little high because this does show 18 or 19 HCP but you do have that five card suit so you should be safe most of the time.

This is the table that will hold all the results.

Summary - Open 1NT or 1♠?

Number of Hands Studied	Which wins?	Percentage
25	1♠ - 12 1NT - 6 Doesn't Matter - 7	1♠ - 48.0% 1NT - 24.0% Doesn't Matter - 28.0%

Hands	Analysis	Verdict
Hand 1 Dealer: North None Vul North ♠AQ754 ♥J76 ♦AQ ♣K42 West ♠KJ983 ♥52 ♦T82 ♣J86 East ♠T ♥AKQT83 ♦J653 ♣T3 South ♠62 ♥94 ♦K974 ♣AQ975 NS 4♣ NS 2♠ NS 1NT NS 1♦	Things do not work out well for N/S on this hand. They need East to come in with their ♥ suit and rescue them. That way East goes down in their contract rather than North. I thought East would come in over 1♠ for sure but await developments if North opened 1NT. However it seems that about the same number of people came into the bidding over both bids. So therefore it really doesn't matter what North opens, East will come in and rescue them. For details you can check out this post: Hand 1	Doesn't Matter
Hand 2 Dealer: East N/S Vul North ♠AT63 ♥83 ♦T86 ♣T965 West ♠J2 ♥AT954 ♦K2 ♣J743 East ♠Q9854 ♥KQJ ♦AQ4 ♣K8 South ♠K7 ♥762 ♦J9753 ♣AQ2 EW 3NT EW 3♥ EW 2♠ EW 2♣ EW 1♦	This is a tough one. I think 3NT will be easier to play and Double Dummy there are only 9 tricks available in both 3NT and 4♥. So the ♥ game can go down. If East opens 1NT they will find their fit and play in 4♥. If East opens 1♠ it is tougher to find their ♥ fit. For details you can check out this post: Hand 2	1♠
Hand 3 Dealer: South E/W Vul North ♠Q43 ♥8 ♦AJ9432 ♣QT3 West ♠AJ62 ♥QT3 ♦K7 ♣A842 East ♠5 ♥J97652 ♦T86 ♣J65 South ♠KT987 ♥AK4 ♦Q5 ♣K97 NS 4♠ NS 3NT NS 3♦ NS 2♣ EW 1♥	If South opens 1NT most people don't have the tools to find their ♠ fit. both 3NT and 4♠ make with no overtricks. So 4♠ will score better. For details you can check out this post: Hand 3	1♠
Hand 4 Dealer: West Both Vul North ♠82 ♥KJ76 ♦QT6 ♣KT63 West ♠KQT65 ♥AT3 ♦A4 ♣QJ9 East ♠J973 ♥Q985 ♦53 ♣852 South ♠A4 ♥42 ♦KJ9872 ♣A74 EW 2♠ NS 3♦ NS 3♣ NS 1NT EW 1♥	I feel that West can always show their ♠ suit IF South competes over 1NT. But what if South does not? Then it is better to open 1♠. For details you can check out this post: Hand 4	1♠
Hand 5 Dealer: North N/S Vul North ♠AK752 ♥Q6 ♦K98 ♣QJ2 West ♠T64 ♥KT543 ♦J ♣A763 East ♠J983 ♥A9 ♦Q32 ♣K854 South ♠Q ♥J872 ♦AT7654 ♣T9 NS 3NT NS 2♦ NS 1♠ EW 1♣	Easier to get to 3NT if North opens 1NT. For details you can check out this post: Hand 5	1NT
Hand 6 Dealer: East E/W Vul North ♠4 ♥AJT5 ♦K9765 ♣Q76 West ♠7653 ♥862 ♦4 ♣KJ984 East ♠KQJ92 ♥KQ9 ♦AJ8 ♣T5 South ♠AT8 ♥743 ♦QT32 ♣A32 EW 3♠ EW 3♦ EW 2♣ NS 1NT NS 1♥	♠ plays better. For details you can check out this post: Hand 6	1♠
Hand 7 Dealer: South Both Vul North ♠74 ♥J76 ♦762 ♣K8742 West ♠KQ9 ♥82 ♦QT843 ♣QJT East ♠852 ♥AK953 ♦K95 ♣65 South ♠AJT63 ♥QT4 ♦AJ ♣A93 EW 2♥ EW 1NT EW 2♦ NS 1♠ NS 2♣	Better to open 1♠ because ♠ plays better if the Opponents don't come in and if they do come in you won't get too high. For details you can check out this post: Hand 7	1♠
Hand 8 Dealer: West None Vul North ♠84 ♥A97532 ♦QJ ♣963 West ♠AJ973 ♥KQ ♦AK3 ♣752 East ♠Q2 ♥J864 ♦T9865 ♣AJ South ♠KT65 ♥T ♦742 ♣KQT84 EW 4NT EW 5♦ EW 3♠ EW 2♥ EW 1♣	I think either opening bid will get the partnership to 3NT. For details you can check out this post: Hand 8	Doesn't Matter
Hand 9 Dealer: North E/W Vul North ♠KQT93 ♥AJ6 ♦KT ♣QJ3 West ♠AJ85 ♥KQT ♦A87 ♣864 East ♠6 ♥9432 ♦J943 ♣KT92 South ♠742 ♥875 ♦Q652 ♣A75 NS 2♠ NS 1NT	I think opening 1NT will stop the partnership from getting too high. For details you can check out this post: Hand 9	1NT
Hand 10 Dealer: East Both Vul North ♠Q ♥Q87 ♦K42 ♣QJT765 West ♠T832 ♥K53 ♦J653 ♣92 East ♠AKJ95 ♥642 ♦AT7 ♣A4 South ♠764 ♥AJT9 ♦Q98 ♣K83 EW 3♠ EW 2♦ EW 1NT NS 3♣ NS 2♥	I think opening 1♠ is better. That allows you to find the major suit fit without relying on the Opponents to come in and help you along. For details you can check out this post: Hand 10	1♠
Hand 11 Dealer: South None Vul North ♠T2 ♥KJ864 ♦Q9 ♣A876 West ♠654 ♥5 ♦JT432 ♣JT43 East ♠QJ3 ♥Q972 ♦A65 ♣Q95 South ♠AK987 ♥AT3 ♦K87 ♣K2 N 5NT NS 5♠ NS 5♥ S 4NT	I think opening 1♠ is better. It either doesn't matter what you open OR bidding 1♠ allows you to play the NT from a better side. For details you can check out this post: Hand 11	1♠
Hand 12 Dealer: West NS Vul North ♠2 ♥Q42 ♦AQ9 ♣AKT743 West ♠AQ876 ♥AKT ♦J72 ♣Q5 East ♠J93 ♥J97 ♦KT8654 ♣2 South ♠KT54 ♥8653 ♦3 ♣J986 EW 5♦ NS 4♣ EW 2♠ NS 1NT	I think opening 1NT is better. It allows the partnership to find the better fit more easily. For details you can check out this post: Hand 12	1NT
Hand 13 Dealer: North Both Vul North ♠AQJ85 ♥AJ3 ♦QJT ♣52 West ♠KT73 ♥8742 ♦963 ♣84 East ♠92 ♥K9 ♦K2 ♣KQT9763 South ♠64 ♥QT65 ♦A8754 ♣AJ NS 6♦ NS 5♥ NS 4♠ NS 3NT	I think opening 1♠ is better. It allows the partnership to find the better fit more easily. For details you can check out this post: Hand 13	1♠
Hand 14 Dealer: East None Vul North ♠QJ4 ♥T876 ♦T43 ♣J86 West ♠7 ♥42 ♦AQ865 ♣AT952 East ♠T9832 ♥AKQ ♦KJ ♣Q43 South ♠AK65 ♥J953 ♦972 ♣K7 EW 3NT EW 5♦ EW 5♣ EW 3♠ EW 2♥	I don't think it will matter what East opens. All roads lead to 3NT just in. For details you can check out this post: Hand 14	Doesn't Matter
Hand 15 Dealer: South N/S Vul North ♠Q9 ♥T ♦J42 ♣AJ98654 West ♠42 ♥J6532 ♦75 ♣QT32 East ♠AK53 ♥KQ74 ♦QT863 ♣ South ♠JT876 ♥A98 ♦AK9 ♣K7 N 3♠/S 1♠ EW 3♥ NS 4♣ NS 1NT NS 1♦	I think South is better off opening 1♠. They are less likely to get into trouble and E/W are less likely to find their fit. For details you can check out this post: Hand 15	1♠
Hand 16 Dealer: West E/W Vul North ♠K2 ♥JT3 ♦JT965 ♣732 West ♠Q8743 ♥A98 ♦AQ8 ♣K4 East ♠AJT6 ♥KQ76 ♦2 ♣AQJ8 South ♠95 ♥542 ♦K743 ♣T965 EW 7NT EW 7♠ EW 7♥ EW 7♣	I don't think it will really matter what West opens. They will easily find their ♠ fit over 1NT with Stayman.	Doesn't matter
Hand 17 Dealer: North None Vul North ♠AKQ96 ♥QT3 ♦AJT ♣T4 West ♠73 ♥J4 ♦KQ8742 ♣J73 East ♠842 ♥AK9862 ♦5 ♣KQ8 South ♠JT5 ♥75 ♦963 ♣A9652 NS 3♠ N 2NT S 1NT EW 1♥ EW 1♦ NS 1♣	I don't think it will really matter what North opens. If they open 1♠ they find their fit but may get to the 3 level since North might invite. If North opens up 1NT and East overcalls 2♥ I feel that the suit is so good North will now bid 2♠. Since 9 tricks are easy to take it won't even matter if they are at the 2 or 3 level.	Doesn't matter
Hand 18 Dealer: East N/S Vul North ♠J642 ♥K82 ♦J3 ♣Q743 West ♠9853 ♥J64 ♦T864 ♣82 East ♠AKQT7 ♥75 ♦A95 ♣KJ5 South ♠ ♥AQT93 ♦KQ72 ♣AT96 N 5♥ S 4♥ N 2NT NS 4♣	I think it will be easier for N/S to find their game if East opens the bidding 1♠. Therefore I am giving the win to opening 1NT. For details you can check out this post: Hand 18	1NT
Hand 19 Dealer: South E/W Vul North ♠JT8 ♥6 ♦Q87652 ♣Q84 West ♠74 ♥A954 ♦K4 ♣AJ732 East ♠A93 ♥J8732 ♦T9 ♣K65 South ♠KQ652 ♥KQT ♦AJ3 ♣T9 2♠ can make by N/S 2♥ can make by E/W 2♦ can make by N/S 2♣ can make by E/W	I think it will be easier for N/S to find their best spot if South opens the bidding 1♠. Therefore I am giving the win to opening 1♠. For details you can check out this post: Hand 19	1♠
Hand 20 Dealer: West Both Vul North ♠KQ986 ♥Q3 ♦K72 ♣T73 West ♠AJT75 ♥85 ♦AQ9 ♣A86 East ♠42 ♥AKT92 ♦JT ♣KQJ5 South ♠3 ♥J764 ♦86543 ♣942 5NT can make by E/W 4♠ can make by W 4♥ can make by E/W 5♣ can make by E/W 3♠ can make by E 3♦ can make by E/W	I don't think it really matters what the opening bid is. E/W will get to 3NT and make the same number of tricks. For details you can check out this post: Hand 20	Doesn't matter
Hand 21 Dealer: North N/S Vul North ♠KQJ74 ♥J2 ♦K93 ♣AK5 West ♠A86 ♥Q3 ♦QJ75 ♣QJ72 East ♠T95 ♥K8 ♦AT42 ♣T843 South ♠32 ♥AT97654 ♦86 ♣96 3♥ can make by N/S 2♠ can make by N/S 1NT can make by N/S 2♣ can make by E/W 1♦ can make by E/W	I think opening 1NT wins on this hand. It helps N/S get to the best contract and stay low in the bidding. For details you can check out this post: Hand 21	1NT
Hand 22 Dealer: East E/W Vul North ♠75 ♥KJ86 ♦AK984 ♣KJ West ♠K962 ♥3 ♦J6 ♣Q87632 East ♠AQJ83 ♥A9 ♦T53 ♣A94 South ♠T4 ♥QT7542 ♦Q72 ♣T5 4♠ can make by E/W 4♣ can make by E/W 1NT can make by E/W 3♥ can make by N/S 2♦ can make by N/S	I think opening 1♠ wins on this hand. It helps E/W get to the best fit. For details you can check out this post: Hand 22	1♠
Hand 23 Dealer: East E/W Vul North ♠JT ♥74 ♦QT953 ♣A764 West ♠753 ♥KJT963 ♦J6 ♣T2 East ♠KQ4 ♥852 ♦K74 ♣KJ83 South ♠A9862 ♥AQ ♦A82 ♣Q95 3♠ can make by N/S 4♦ can make by N 2NT can make by S 3♦ can make by S 1NT can make by N 2♣ can make by N/S 1♥ can make by E/W	Doesn't really matter what South opens. The partnership will end up in 1NT and realistically both sides take 8 tricks. For details you can check out this post: Hand 23	Doesn't matter
Hand 24 Dealer: West None Vul North ♠KT ♥AK8 ♦653 ♣Q9875 West ♠AQJ83 ♥Q4 ♦K92 ♣K62 East ♠954 ♥JT52 ♦QJ8 ♣T43 South ♠762 ♥9763 ♦AT74 ♣AJ 1NT can make by N/S 2♦ can make by N/S 2♣ can make by N/S 1♥ can make by N/S 1♠ can make by E/W	1♠ works best here. It allows you to get to your last making contract. For details you can check out this post: Hand 24	1♠
Hand 25 Dealer: North E/W Vul North ♠AJ654 ♥AJ9 ♦A3 ♣K85 West ♠ ♥T754 ♦KQ75 ♣QJT93 East ♠KQT87 ♥82 ♦J86 ♣A64 South ♠932 ♥KQ63 ♦T942 ♣72 1♠ can make by N/S 1NT can make by E/W 2♣ can make by E/W 1♥ can make by W 1♦ can make by E/W	1NT works best here. It allows for the fact that East (or West) might come into the bidding and the Opponents will get too high OR it stops the N/S partnership from getting too high in their ♠ fit. For details you can check out this post: Hand 25	1NT