Manx Diamond MANX DIAMONDStrong Club System

Partnership reference · updated 9 July 2026

Every agreement,
one card away.

The complete Manx Diamond strong-club system — opening bids, responses, slam tools, defence and competitive auctions — organised so you can find an answer at the table in seconds.

System: Strong Club (16+) Structure: Multi-landers, 2-over-1 Vulnerability-adjusted: Yes
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Opening Bids

9 opening bids

Points are NV / V (non-vulnerable / vulnerable) minimums unless stated. MD = multi-landing / asks for a 4-card major.

BidOpener's HandResponder's OptionsOpener Rebid
1♣ 16+ NV / 17+ V Cannot pass. 1D=<8pts. 8+pts=bid 5-card major. 2C=8+ both minors. 2D=8+ both majors (MD). Jump major=weak 5-6pts 6-card. 1NT=8-10 (may have 4-major). 2NT=11-13 (may have 4-major). 3NT=14+ (all controls, slam invite). Jump 22+ in suit. 1NT=16-18. 2NT=19-21. 3NT=22+ all controls. Stayman (both 1NT/2NT) finds major fit; then 4NT=5-ace Blackwood, 4C=aces over NT.
1♦ 11-15 NV (no 5-major, min 2♦, may have singleton club) Pass if weak with 4+♦. Natural if weak but bid any 4-card major. Weak 2s ok. 1NT=no major 6-9. 2C=10-12 minors or 4-major. 2D=game try (MD for majors). 2NT=16+ all controls. Natural — treat MD like Stayman; 2NT denies 4-major. After 2C, opener's 2D (MD) asks for 4-major; none=2NT sign-off.
1♥/1♠ 11-15 (5 cards; repeat=6) Natural 8-10 to level of fit. Natural 10+ new suit 2-over-1. Jump out 14+ game force. 1NT=8-10 2-card support. 2NT=16+ no 4-card support. Natural. 4NT for Aces (except 4C over 2NT for Aces).
2♣ 12-15 NV / 13-16 V (any singleton/void except ♣, one 4-major; min 3♣) Cannot pass unless weak, with clubs length & poor majors. Bid longest suit — except: 2D (MD, non-promissory) invites opener's 4-major. 3D strong (MD) asks for 4-major. Repeat ♣ if suit length, but MD from responder=bid 4-major. 2NT=sign-off if unfavourable (e.g. length in singleton major).
2♦ 12-15 NV / 13-16 V (void/singleton♦, no 5-major, two 4-major — MD opening seeking major fit) Cannot pass — MD opener. Natural; bid 4/5-major at 2-level if weak. 3D=strong+major interest (MD). 3C=4♣ no 4-major, weak. 4C(suit)=strong game invite ♣. 2NT=♦ control twice. 3NT=14+ with ♦ control twice. Natural to level of fit. Pass with 4-card support. Bid best major after 3D (MD); control passes to Responder.
2♥/2♠ Weak 6-10 (6 cards) Natural to level of fit. 2NT=asking quality (Ogust). 3C=low HCP weak, 3D=low HCP good, 3H=high HCP weak, 3S=high HCP good, 3NT=AKQJxx
3♣/// Weak 6-10 (7+ cards) Natural. Raise to 4 with outside strength 16+ & 2-card support. Natural if game likely.
1NT 13-15 NV / 14-16 V 8+ Stayman & transfers. 2NT=invite to 3NT if max. Natural; control passes to responder after Stayman.
2NT 13-15 both minors 5+ Bid better minor. Natural but careful when V.

No bids match your search.

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Slam Bidding

Minimum for slam: 28 pts & 9 combined cards when cross-ruff if void/singleton. Otherwise 31+ points.

NT Slam — Aces (4C)

4D=04H=1 4S=24NT=3

Suit Slam — Aces (4NT), 5 Aces*

5C=0/35D=1/4 5H=25S=2+Q trumps

NT Slam — Kings (5C)

5D=05H=1 5S=25NT=3

Suit Slam — Kings (5NT)

6C=06D=1 6H=26S=3 · 6NT=4

*King of trump suit = 5th ace (when suit agreed or implied).

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Defence & Signals

  • Ruff signal: High card = want higher suit back as entry. Low card = want lower suit back.
  • Discard: Low = lower of other 2 suits. High = higher. Middle (6/7) = suit may be ok.
  • Play in suit: High = hate. Low = love.
  • Count: High-low = even cards. Low-high = odd cards. Giving count is important.
  • Leads: Ace led = also has King. King led = also has Q. Q led = QJ10. J led = J109+.
  • Leading partner's suit: Lead highest to clarify distribution.
  • vs NT: 4th highest unless internal sequence (e.g. Q1098x → lead 10). Rule of 11 applies.
  • Leading partner's suit may be dangerous if opponents overcalled into NT.
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Interference Strategy

  • After opp 1NT: 2C=minors, 2D (MD)=majors, X=penalties (16+).
  • After opp suit bid: X=opening pts no stopper. 1NT=stopper 14-16 pts. Bidding their suit=17+ (next level). NT overcall if borderline.
  • Doubles: First chance=takeout. Second chance=penalties. Doubling an artificial bid (transfer, cue bid etc)=length.
  • Weak jump overcall: 6-9 pts, 6-card suit. 3-level jump = 8-12 pts.
  • Single overcall: 8+ pts, 5-card. 2-level overcall: 10+ pts, 5-card. 2NT=5-5 minors (unusual NT); strong club hand may still open.
  • Alert any bid 2-level and below.
  • Over our 1C if interfered: Pass <5pts. X=takeout 6-9 (short in their suit). 10-15pts (or stopper)=bid nearest NT (forcing to game). 15+pts=bid their suit (slam interest).
  • Over our 1D if interfered: X=I have the other major. NT over a major=I can stop this major. Or bid opposition suit at next level=game interest.
  • If 1NT (13-15) interrupted, systems on. Opp 2C over partner 1NT → X=majors (Stayman), 2D=transfer to ♥ etc.
  • If opp double our 1NT (penalties): Leave with 5+ pts. Escape via transfers with ≤5 pts to 6-card suit. Redouble=SOS asking opener to look for weak fit in minors.
  • Opp open 3 minor: X=takeout. 3 major: X=penalties, 3NT=takeout.
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General Bidding Rules

  • Openings: rule of 19 at one-level, rule of 20 at two-level. 11 points flat, 1D is a pass.
  • Fourth-in-hand 1D opening is rule of 15 — points plus number of spades. Further bids natural or artificial by agreement.
  • Cannot pass with void or singleton support — consider cross ruffs on any trump fit.
  • Bid to level of fit: 8 cards = level 2, 9 cards = level 3.
  • If maximum, consider another suit as forcing one round, then support partner later.