This is a set of notes I've been using with a bridge partner which is based on Marston's 2 over 1 book (5th edition, with semi-forcing NT). This document isn't intended to be complete or even really make sense outside of the context of looking something up in this partnership that has agreed to use this system.

As we're both beginners (I wrote this up after playing bridge for about one month), the system is fairly simple and doesn't include a lot of gadgets that are described in Marston's book.

General 2/1 structure questions

• Is 1D-2C game forcing?
  • Yes
• Does 1NT semi-forcing response deny opening bid values
  • No
• Does opener's rebid of own suit guarantee 6
  • Yes
• Does direct raise of responder's minor show extra values, e.g., 1H-2C-3C
  • No?
• Does opener's 2-level reverse show extra values (within 2/1 auction)
  • No
• Does opener's high-level reverse (e.g., 1H-2D-3C) show extra values
  • No
• If responder rebids their minor, is it forcing? E.g., 1S-2C-2S-3C
  • IDK, but I think yes?

1NT

• 1NT is generally higher priority than opening a 5-card major; open 1NT with almost every 5-3-3-2 hand
  • May open 1NT with two doubletons (see https://www.larryco.com/bridge-articles/opening-1nt-with-2-doubletons)
  • Open 1NT in rare cases with a 6-card minor (https://www.larryco.com/bridge-articles/when-to-open-an-off-shape-notrump)
  • Open 1NT with 4-4-4-1 or 5-4-3-1 if the singleton is Q or higher and you wouldn't have a good rebid if not opened NT.
    • KQ87/K/AKJ65/832 and KT65/K32/Q/AKJ76 would be opened 1D and 1C, respectively
    • K/Q765/AQJ/AT876 would be opened 1NT because there's no good rebid after opening 1C (not strong enough to reverse but nothing else to bid)
    • Same for two doubletons; K2/42/AQ765/AQ42 can be opened 1D and rebid to 2C, so open that 1D
    • But 32/AQJ8/52/AKJT6 has no good rebid if opened 1C (15 points, don't want to rebid 2H and reverse), so open that 1NT
• Stayman: [from https://www.bridgewebs.com/northbay/BB10%20-%20Larry%20Cohens%2012.pdf]
  • holding 8-9 HCP and one or two 4-card majors, responder bids 2♣ over 1NT to ask if opener has 4-card major. Without such, opener bids 2♦.
  • With two 4-card majors, opener bids hearts first.
  • If opener bids the major in which you hold less than 4 cards, bid 2NT (with 10+ HCP, bid 3NT)
  • Opener will know you have 4 cards in the unbid suit.
• Beginner structure for when opponents interfere:
  • Over opponents double, systems on as usual
  • Over their 2C, our X is Stayman
  • Over their 2D/2H/2S
    • X is negative
    • Bidding a suit at the 2-level is weak and shows 5-7 cards
    • Cuebid of their suit is GF Stayman
    • All higher bids starting at 2NT are as if they didn't bid
  • Can use lebensohl if we want a more sophisticated system

Semi-forcing 1NT response (1M-1NT)

• Semi-forcing off when passed hand
• Shows 6-12 HCP (assuming not a passed hand — forcing is off if passed hand)
• Opener's options:
  • Pass with a balanced minimum. Examples from book are pass with
    • AJ862/Q42/J7/KJ2
    • A8763/J72/AQ3/J5
  • Semi-forcing bit: we generally respond if we have 13 or 14 HCP
    • if we can't rebid our suit or legitimately bid a new suit, we bid a 3-card minor
    • Book suggests using judgment on this and suggests passing hands like AQ64/Q9854/K8/K2 (example is 14 HCP)
• When opener has a strong unbalanced hand: need to jump to avoid missing game since opener's response isn't forcing.
  • Jumping in a new suit shows 18-19 HCP
  • Jump rebid of own suit shows 15-16 HCP
  • With AQJ72/KQ87/2/AK3, book suggests 1S-1NT-3H
  • With 2/KQJT87/Q62/AK3, book suggests 1H-1NT-3H
• There's some material on how to do a 3-card limit raise in the book I haven't read. Maybe we can revisit this later?

1m

• If 3-3 minors, open 1C: this causes 1D to almost always be at least 4 diamonds

Responder

• 2m raise: 10+ HCP, usually 5-card support, but could be 4 with no better bid (would usually bid a 4-card major if we had it)
  • Opener's rebid of 3m is a minimum with 6 cards (not sure why this is the case; should re-check book)
• 3m raise: 6-9 HCP, 5-card support
• 1NT: 6-10 HCP, denies 4-card major
• 2NT: 11-12 HCP
• 3NT: 13-15 HCP, balanced hand. Strongly try to avoid this response

Inverted minors off in competition

1M

• If 5-5 in both majors, open 1S
• 3rd/4th seat: can open 4-card suit if not vulnerable and good suit (3 of top 5) and below minimum opening values
  • Must pass response if we open light so partner can distinguish a light opening and a real opening
• 4th seat: if we can choose to pass it out, don't open if we think opponents have spades since they're relatively likely to be able to play in spades; conversely, be more willing to open in 4th seat if we have spades

Responses

• Single raise shows 6-9 TP
• With 5-card support and 6-9 TP, raise directly to game
  • May not make, but likely to want to sacrifice if we don't make
• Jump raise: limit raise, showing 10-12 TP and usually 4-card support with no singleton (with singleton, could bid a splinter)
• Jacoby 2NT: game forcing with 4-card support (see Jacoby 2NT section)
• [shouldn't use until we discuss, but this seems standard and is in the book] passed hand responses: Drury
  • Goal of this convention is to avoid going too high when partner made a light opening in 3rd seat
  • 2C shows 3-card support for partner's major and 9-11TP
    • Opener replies with 2 of major to show light opening bid; any other reply shows normal opening bid
  • Drury is off if the opening bid is overcalled or doubled

Opener's rebids

How many points are promised?

• Supporting partner's suit at lowest level: 13-15 TP (I guess this can't be 12 because we should have a doubleton or have opened with a distributional handle that gives is more shortness points if we had < 12 HCP?)
• Jump raising partner's suit: 16-18 TP
• Direct raise to game (major suit): 19+ TP
• Bidding a new suit at the 1-level: 12-17 HCP
• Bidding a new suit at the lowest level at the 2-level (e.g., 1H-1S-2C): 12-17 HCP
• Single jump raise to 3 level (e.g., 1D-1S-3C): 18-19 HCP
• Bidding a reverse: 16-19 HCP
• 1NT: 12-14 HCP
• 2NT: 18-19 HCP
• Rebidding own suit at lowest level, 2-level: 12-15 HCP
  • Jump rebidding own suit, 3-level: 16-18 HCP

What do our rebids mean when partner raises our minor?

• 2NT: balanced, minimum
• new suit, e.g., 1C-2C-2H: at least 4-4 shape in the two suits, 12-19 HCP (this doesn't narrow point range!)
• minimum re-raise, e.g., 1D-2D-3D: minimum with 6 of the minor
• TODO: figure out other situations? This doesn't cover a bunch of stuff!

Responder's rebids

i.e., responder's 2nd bid

• If weak (6-9TP): try to get out below 2NT
  • This might mean passing, e.g., if bidding is 1D-1H-2D and we have a singleton diamond and no good suit, pass
  • Returning to opener's suit at 2-level (e.g., 1H-1S-2C-2H) is weak
• Invitational (10-12 HCP)
  • Raise opener's minor suit to the 3-level ("belated support") [belated support of major is forcing, not invitational]
  • Raise opener's 2nd suit (need 4-card support for this)
  • With no other bid, can bid 2NT (shows 10-12 HCP and values in at least some of the unbid suits)
  • Invite of 2NT if opener raised our major is saying opener should revert to our major with 4-card support 3M or 4M depending on strength) or play in NT (2NT or 3NT) with 3-card support
    • This allows partner to raise with 3 and for us to find 5-3 fits
• Forcing (13+ TP) [book seems to mean for one round and not game forcing???]
  • Returning to opener's major at 3-level (e.g., 1H-1S-2S-3H)
  • New suit, e.g., 1C-1S-2C-[new suit]
    • Above is not forcing if opener rebid 1NT, e.g., 1C-1NT-2H is not forcing; to force after 1NT, need to jump, so bid 1C-1NT-3H instead of 2H
• Game forcing
  • Responder's reverse
• Vs. Opener's reverse when our response was at the 1-level
  • we can't pass, but any minimum response we make is not forcing, e.g. 1D-1S-2H-2NT or 1C-1H-2D-2H
    • This is because we could have as few as 22 HCP (16 + 6), so need a way to stop short of game
  • To force, make jump bid or use 4th suit forcing
• After we initially raised partner's minor
  • Bid of 2NT or 3m is to play
  • Above means that we don't have an invitational NT bid; need to bid 3NT if we want to play in NT game

2/1 auctions

• single jump shift is a splinter, showing a fit and shortness (singleton or void) in the bid suit.
  • splinter bid is usually a priority, except if the fit is in a minor and we haven't bid our 4-card major. In that case, bid the major first. In this case, we can bid the minor later, which will still imply shortness
  • splinter bid shows fit to last bid suit, e.g., with 1S-1C-1NT-3D, 3D is a splinter showing a fit in spades and shortness in diamonds
  • after a splinter, evaluate slam by ignoring all points in the short suit, except for A, which is worth 2. If splinter points >= 26, look for a slam
    • Count partner as 12 HCP for an opening bid or 10 HCP for a splinter (this 10 HCP splinter is if they splinter in response to our opening, not in the context of a 2/1 auction, where we expect both parties to have >= 12 HCP)
• Fast arrival is on, so if we have a fit and directly bid game, that shows a minimum w.r.t. our remaining possible range. If we bid a lower raise, that shows extra values
• Opener's responses to 1D-2C special case bids: not using this right now, should revisit later
  • 5D: always bid with 5 diamonds. All other bids deny 5 diamonds
  • 2H: 4 hearts, balanced or 4-4-4-1 or 1-4-4-4
  • 2S: 4 spades and 4 diamonds, balanced, possibly 4-1-4-4
  • 2NT: not 5 diamonds and no major, so 3-3-4-3
  • 3D: solid suit (KJTx, AKQJxx, etc.)
• Opener rebidding their suit shows an extra card in the suit (e.g., rebidding spades or hearts shows 6)
  • Opener's jump rebid of their suit shows "a solid 6-card suit" (no losers or one loser in the suit, something like AKQxxx, KQJ10xx, etc.); sets the trump suit and asks partner to start control bidding
    • This is apparently somewhat standard and not just a weird thing from the book? This is also suggested by https://www.advinbridge.com/this-week-in-bridge/421

Jacoby 2NT (1M-2NT)

Opener's response

• 4 of new suit: 5-card suit (at least 5-5 shape)
  • Priority bid if 5-card suit is pretty good (say, Axxxx or maybe even Kxxxx or better)
• 3 of new suit: shortness (singleton or void)
  • Priority bid unless we have a good 5-card suit to show
• 3 of opened major: 17+ TP, denies shortness
• 3NT: 15-16 TP, denies shortness
• 4 of opened major: minimum

Strong 2C opening

Generally shows 20+ HCP or 22+ HCP balanced (with 20-21, would bid 2NT). Can upgrade to 2C if hand is good (lots of A/K) or downgrade 21-22 HCP hand if bad (honors in short suits, lots of Q/J). Maybe skip 2C with up to 23-24 HCP if hand is short in majors and long in minors.

With balanced hand, open 2C then rebid 2NT with 22-23, 3NT with 24-26

Game forcing unless opener rebids 2NT

Responses * 2D negative: 0-7 HCP * 2H/2S/3C/3D: 8+ HCP, 5 cards in the suit * 2NT: 8-10 HCP * 3NT: 11-13 HCP

Opener's rebids * Any new suit shows 5 in that suit * Jump shows a solid suit (https://www.advinbridge.com/this-week-in-bridge/421), similar to jump raise of own suit in 2/1 auction and sets trump * Reasoning here is that any suit bid is already forcing and there's no need for a weak jump bid, so jump bid must show something else

• Fast arrival is on when choosing level if there's a fit
  • Responder jumping directly to game opener's suit is a minimum
    • This means 0-5 TP if responder previously bid 2D negative; if positive response, minimum given positive response
    • Above implies 6-7 TP by responder if bidding goes something like 2C-2D-2S-3S

Note that many people play 2D as a "waiting" response and not "negative", so it may not deny values if someone else bids it. Some people (this seems old school and not super common among younger players?) also play transfers on to 2C and some people use 2H as a "double negative" response that's 0-3 HCP.

The convention card we looked at has a more complex and probably better structure, but 2C auctions are so rare just using this simple structure seems fine for now? If you prefer the more complex structure, I don't mind switching to it, though.

Weak 2 (preempts)

• Responder's immediate 3NT response ends auction
• 2NT asking bid, responses
  • Opener responds with 3 of their suit with a minimum, 3 of suit with an outside feature (other honor) if maximum.
  • With AQJxxx or better, opener bids 3NT
  • If responder bids 2NT and then 3NT, opener has the option to bid 4M with a shapely hand
• Responder's 4C at any time asks for aces (would normally be keycard if we were playing keycard)

Overcalls

What do we need to overcall?

• 1-level overcall shows a 5-card suit, 2 points weaker than an opening bid, so response range is adjusted appropriately. Usually not more than 18 HCP since we'd double instead
• 2-level overcall usually 6-card suit; could be good 5-card suit if opening hand strength
  • From iwolff2357: "When vulnerable, It takes about an opening hand with a very good suit, or better than an opening hand with a good suit. When not vulnerable, some strong players like to stick in lead directing 2 level overcalls. So those will still show a very strong suit, but could be less than an opening hand."

Overcall specifics

• Over call responses
  • single raise or 1NT: 8-11 TP
  • jump raise or 2NT: 12-14 TP
  • new suit: 8-14 HCP; not forcing, but new suit should be overcall quality
  • jump to new suit: 15+ HCP
• 1NT overcall shows 15-17 HCP and stopper in opponent's suit
• Jump overcall is weak, like a weak two pre-empt
• Takeout double means opening hand with 3-card support for unbid suits, or very strong hand; responses below
  • 0-9 TP: bid your suit at the cheapest level. 1NT shows balanced hand with 6-9HCP and stopper
  • 10-12TP: jump raise or 2NT
  • 13+TP: bid game
• Double followed by NT bid is 18+ HCP
• Overcalling their 1NT: see 1NT defense section
• Overcall of 3-level pre-empt (not sure why the book describes this in the overcall chapter but not overcall of 2-level preempt): 6-card suit and 11-15 HCP (with 16+ HCP, bid game)
• Overcall of 2-level pre-empt (from some pro on discord)
  • natural suit bid starting at a sound opening
  • double is takeout, as usual
  • 2NT: 15-18 HCP, double stopper in pre-empt suit
    • Can play usual NT structure over this
    • maybe for later (definitely not using now): lebensohl in response to partner's takeout double
• Doubling 3 or 4 level opening: for takeout, similar requirements as 1-level takeout double, with increased priority if we have shortness

Conventional Overcalls

• Unusual 2NT (jump to 2NT): 8-12 HCP, 5-card suit in the lowest two unbid suits
  • Only bid if we have a good chance of playing. Bid is very revealing about our hand.
• Michaels cuebid: shows both majors when cuebidding minor; shows other major and a minor when cuebidding major
• Leaping Michaels: [this is new] 4m jump overcall of weak 2, promises two-suited hand with at least 5-5 shape
  • 4C over 2D/2H/2S: shows clubs and the unbid major (unspecified major if over a minor)
  • 4D over 2H/2S/3C: shows diamonds and the unbid major (unspecified major if over a minor)
  • 3H/3S cuebid (over 2H/2S) shows a strong balanced hand; asks partner to bid 3NT with a stopper

When opponents intervene

• Responder, after opponents overcall opener's opening bid
  • Raise opener's suit whenever possible; single raise shows 6-9 TP
  • Jump raise shows invitational values
  • 1NT shows 6-9 HCP, stopper
  • 2NT shows 10-12 HCP, stopper (Jacoby 2NT off)
  • New suit promises 5 instead of 4. "Regarding strength, the only change is that a new suit at the two level is no longer forced to game. It is only forcing for one round, promising no more than about 8 HCP" [I believe this phrasing means that it promises roughly 8+ HCP]
  • New suit at three level is game forcing, e.g., 1D-(2S)-3H is game forcing sequence after opponents overcall 2S

• Responses, after opponents double opener's opening bid:

  • new suit at the 1-level is as before, 4+ cards and 6+ HCP
  • new suit at 2-level is different: 5-card suit and 6-9 HCP, vaguely pre-emptive
  • 2NT: 4-card support for opener with at least 10 HCP (if we had a genuine NT bid, we'd start with redouble)
  • jump to 3 of partner's suit pre-emptive, 6-9 HCP with 4-card support
  • redouble: 10+ HCP; usually with shortage in partner's suit and therefore an interest in penalties. We can double any suit opponents bid

• Opener's 2nd bid after interference (conventional, not double): new suit shows a 5-card suit, forcing for 1 round

• If overcall is passed back to us and we have shortness in opponent's suit, double (e.g., if we open 1H, opponents bid 1S, and it comes back to us and we have something like 2-5-3-3 shape). Do not need extra strength for this

  • Note that we need to do this so that partner knows they can penalty pass before we've doubled if we have shortness and they think opponents have a misfit
  • unlike a double. a re-opening bid after partner has passed does show extra strength. 1NT would show 18-19 HCP and a stopper (a hand that would've bid 2NT over the opening without interference)

• Negative double (we open and opponents overcall, for example, after partner/opener bids 1C and opponents bid 1S): shows 4 cards in any unbid major and 6+ HCP

  • A negative double can ONLY be made by responder, and occurs when responder doubles a direct overcall after a 1-level opening
  • Negative double at 1-level shows 6+HCP. At 2-level, 8+ HCP. At 3-level, 10+HCP
  • Higher negative doubles have no guarantees, except an ability to ‘control’ the auction if partner bids an unbid major
  • Negative double promises
    • 1D: 4-4 majors
    • 1H: exactly 4 spades (would bid 1S with 5+)
    • 1S: 4+ hearts. If 5+, shows hand is too weak to bid 2H directly (negative double of 1S is like bidding 1H after opponents have bid 1S)
  • Opener's rebid of negative double, bidding a new 4-card major at the 1-level
    • 2-level: 13-15 TP
    • 3-level: 16-18 TP
    • 4-level (game): 19+ TP
    • 1NT shows 12-14 HCP with a stopper
    • Book's section on this is highly incomplete, no more examples/structure provided, except maybe in exercises

• Penalty vs. negative double:

  • 1-level: always negative
  • if partner opened at 2-level or higher, double is always for penalty because partner has described their hand
  • game: for penalty

• Support double (we open, partner responds 1M, RHO overcalls): 3-card support for partner's major (direct raise would show 4) [I'M GOING TO ASSUME WE'RE NOT USING THIS UNTIL WE DISCUSS IT]

  • Not doubling denies 3-card support

1NT defense

(from the linked convention card, except doesn't change when playing against weak vs. strong NT since we basically never run into weak NT at the club level).

Bid fairly light (bid with 8HCP with one or two good suits).

• 2C: 5-4 majors (rarely 4-4)
• 2D: 6+ card major (rarely 5) without a side suit
• 2H: 5H, 4m
• 2S: 5S, 4m
• 2NT: both minors
• Double (against strong NT): 4M-5m
• Double (against weak NT; rare): penalty (bid if 15+ points, less if playing against weak NT)

Responses to above (TODO: how many points to respond if opponents intervene???)

• 2C
  • respond with best major, or 2D if equal length
• 2D
  • Normally bid 2H, but bid 2S if prepared to go to 3H or above in hearts; opener corrects
• 2H/2D
  • pass or bid 2NT to ask for the minor
    • Opener can correct 2NT to their minor
• Double as 4M-5m:
  • 2C is pass or correct; overcaller passes with clubs or corrects to 2D
  • 2D asks overcaller to bid the major or pass with 1-suited
    • This seems to imply that you can also double with long diamonds and no major, since overcaller is allowed to pass this
• Double: responder passes unless hand is very weak, in which case they'd bail out to a 5-card suit or still pass with balanced hand

1430 KC

• 4NT is keycard for agree suit; if no agreed suit, it's KC for last naturally bid suit
  • 5C: 1/4
  • 5D: 0/3
  • 5H: 2/5, no trump Q
  • 5S: 2/5, trump Q
• after 5m, next step (skipping KC suit) asks for trump Q
  • Responder bids KC suit without Q

Misc

• When is it not a reverse?
  • A reverse shows extra values when there aren't known extra values because responder would have to correct back at the 3-level.
    • If extra values have been shown (GF auction, inverted minor response, etc.), opener's reverse-like bid never shows extra values
    • If we're supporting partner's suit, that's not a reverse because partner shouldn't need to correct back to our suit, e.g., in 1C-1H-2H, 2H is not a reverse (it actually shows a minimum, <= 15 TP)
• What sets the trump suit (meaning that 4NT is blackwood, bids of other suits are control bids, etc.)?
  • Anyone showing a solid suit (opener's jump rebid of own suit in 2/1 auction, opener's jump bid of a suit immediately after strong 2C opening, Gambling 3NT)
  • Jacoby 2NT (opener's suit is now trump suit)
  • Splinter bid (single jump shift in 2/1 auction or double jump shift response in standard auction)
  • More generally, any agreed upon fit

Gambling 3NT opening [SHOULD DISCUSS BEFORE USING THIS]

This rarely comes up, we should discuss if we want to do this now or defer until later. Apparently no one really plays the 3NT as meaning some point range, so people put something else in place of the standard beginner 24-26 HCP for 3NT and this is the most common replacement.

Shows 7+ card solid suit in a minor. Denies void or 4+card major.

Responses

• pass: want to play in 3NT
  • Partner is good for 7 tricks, so we only need 2 more to play in 3NT as long as we think opponents can't take 5 before we get our tricks
• 4C: pass or correct (says we prefer playing in partner's minor over 3NT)
• 4D: asks for shortness
  • 4M: short M
  • 4NT: no shortness
  • 5m: short OTHER minor, i.e., respond in your long suit
• 4M: to play