Once you have decided that your hand is worth an opening bid, we now turn to what to open. Our first priority is to open 1NT, as that is the most descriptive opening. If we cannot open 1NT we check to see if we can open 1M (1♥ or 1♠). If we cannot open either 1NT or 1M, we turn our attention to a 1m (the lowercase m here denotes a minor suit, clubs or diamonds) opening bid. Note that all hands worth an opening bid (12-21 points) can (and should) be opened at the 1-level (with rare exceptions).
Requirements for opening 1m
12-21 total points (HCP + length points)
At least 3 cards in the minor opened
If you have a choice between two suits of equal length, open the HIGHER RANKING suit
Exception is if you have 3 clubs and 3 diamonds - in that case open 1♣.
If you can open 1M or 1 notrump, open those instead of 1m
We have 13 HCP and 0 length points which add to 13 total points. Therefore we want to open the bidding. We cannot open 1NT because we do not have either the appropriate strength or the appropriate distribution, so we check if we can open 1M. We cannot open 1M because we do not have a 5 card major. However, we can open 1 of a minor suit with 4 cards in each minor. We want to open the higher-ranking suit, which is diamonds, so open 1♦.
We have 13 HCP and 2 length points (1 in hearts and 1 in diamonds). Therefore we want to open the bidding. We cannot open 1NT because we do not have either the appropriate strength or the appropriate distribution, so we check if we can open 1M. We have a 5-card heart suit, so we should open our hand 1♥.
Responding to a 1m Opening Bid
When partner opens 1m, responder follows the same guidelines for whether to respond or not as over a 1M opening: with 6+ points or good support you must respond, otherwise generally you should pass.
Responder’s options are (in order of priority):
Bid a major at the 1-level
Support partner’s minor
Note that unlike after a 1M opening, supporting partner is not a priority; responder should bid a new major suit even with support for opener’s minor. This is because finding and getting to major suit games are extremely important, so that should be the first priority. The minor suit can always be raised in the next round of bidding if no major suit fit is found.
4-card or longer suit
While 1♥ and 1♠ openings require 5+ cards, responding to a 1m opening with a 1♥ or 1♠ response only requires 4. This is because opener can have a 4-card major as well, so the partnership could have 4+4 = 8 cards in the major.
If 1♥ and 1♠ are both possible bids, choose the longer major. If the length are the same, respond with 1♥ with 4-4 in the major and with 1♠ with 5-5 in the major.
If responder had not passed before during the auction, this bid is FORCING. Opener may not pass because responder can have unlimited values! It will be a shame to play in 1M when you can make a grand slam!
Raising opener’s minor
In general, because opener can have as little as 3 cards in the minor opened, responder should have at least 5 card minor suit support to raise the minor. However, in the majority of cases opener has at least 4 cards in their minor, so responder can consider raising with only 4 card support.
However, one distinction between raising after a 1m and 1M opening is that over a minor opening 3NT is usually still the most likely game, meaning that it is generally better to find alternatives with balanced or semi-balanced hands.
As a guideline, avoid counting support points when raising opener’s minor suit unless your hand is very unbalanced and you have no intention of playing in notrump.
With no 4-card or longer major and no distributional support hand, you can look to bid notrump.
Partner opens 1♣ or 1♦:
6-10 points, respond 1NT (to show little, but some, values)
11-12 points, respond 2NT (invite game)
13-15 points, respond 3NT (13+12=25, enough for game)
A response in NT is non-forcing, meaning opener can pass
Your partner opens 1♣. For each hand, determine your response.
Pass. You only have 3 HCP. A response usually shows at least 6 points.
1♠. Introducing a major suit is important because it can potentially lead to a major game. Supporting your partner in clubs can be delayed.
1♥. You have the length to bid either major, so you should bid the longer one.
1♠. You choose spade over diamonds at first because spade is a major suit. Also, with equal length at 5, you typically bid the higher ranking suit.
1♥. You have the length to respond with either one of the majors. With 4-4, 1♥ is the correct response since it gives partner the space to bid 1♠.
1NT. You have 8 HCP, no 4-card major, and a balanced hand.
2♦. You do not have a 4-card major, but you do have 7 HCP + 2 length points, and 5-card support for partner.
3NT. You have 14 HCP, enough for game. You do not have a 4 card major to bid. Your hand is also balanced, suited for playing in NT.