Open a PBN file, let all four seats produce a teaching Acol auction — including balanced-hand evaluation, weak twos, pre-empts, Pender–Flint, Stayman/transfers, Puppet Stayman, CRO, forcing bids and Gerber slam investigation — audit the resulting contract double-dummy, then choose the opening lead.
1. Load Board→2. Show Bidding→3. Choose Lead→4. Review
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Boards
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Board
Hand diagram · HCP shown
Double-dummy audit
Waiting
Show the bidding first.
Choose the opening lead
Should I lead a trump? — auction-only test
Your turn. Click the card you would lead. The answer uses the Cardiff Bridge Tutors hierarchy: choose the suit first, then the card. Against a major-suit fit, the other unbid major is a prime attacking suit; card-selection rules are applied only after the suit is chosen.
Lead analysis
How the auction selected the suit, then how the carding rule selected the card.
Teaching Acol Rules
Reference rules used by the bidding and opening-lead engine.
Balanced shapes: 4-3-3-3, 4-4-3-2 and 5-3-3-2. A five-card heart or spade suit is still balanced when there is no four-card side suit. Weak 1NT is fundamentally 12–14 actual HCP: a genuinely balanced 12–14 HCP hand opens 1NT even if positive hand-evaluation adjustments take the evaluated total above 14. Evaluation may also bring a borderline hand, such as a poor 15-count, into the weak-NT range. 2NT is 20–22 evaluated points. A 5-3-3-2 hand with a five-card major in the 1NT range opens 1NT rather than the major.
Balanced-hand evaluation (“Goodies and Baddies”): deduct 1 for 4-3-3-3; add ½ for a five-card suit (1 for a good-quality five-card suit); add ½ for supported honours; add ½ for each 10 or 9 supporting an honour; deduct ½ for an isolated honour; add ½ for an honour in a suit bid naturally by partner. These adjustments are used only on balanced hands for NT/opening/rebid/invitational decisions. For automation, a “good-quality five-card suit” means two of the top three honours (A/K/Q) or three of the top five honours (A/K/Q/J/10).
Weak twos: 2♦, 2♥ or 2♠ with a six-card suit and roughly 6–10 HCP. 2♣ remains the strong opening.
Pre-empts: a seven-card suit may open at the three level; an eight-card suit may open at the four level, normally with a weak hand.
Otherwise a one-level suit opening is used from normal opening strength, with four-card majors recognised.
Competitive actions include natural one- and two-level overcalls, a 15–17 1NT overcall with a stopper, CRO (Colour–Rank–Other) for suitable 5-5 two-suiters over an opponent's one-level suit opening, take-out doubles, negative doubles, penalty doubles, redoubles, responses to doubles, competitive raises and descriptive rebids. Over an opponent's 1NT opening, natural suit overcalls use the Rule of 8: add the lengths of the two longest suits, subtract Losing Trick Count; with at least 6 HCP, enter when the result is 2 or more. A natural overcall still requires a five-card or longer suit in this teaching engine.
CRO: with at least 5-5 in two of the three unbid suits and useful values concentrated in those suits: cue-bid opener's suit = the two suits of the same Colour; 2NT = the two suits of the same Rank (majors or minors); 3♣ = the Other two suits. Partner chooses between the two explicitly shown suits; the artificial CRO denomination is not treated as a natural suit.
Law of Total Trumps in competition: once a fit is known, compete approximately to the level of the partnership trump count — 8 trumps → 2-level, 9 → 3-level, 10 → 4-level, 11+ → 5-level in this teaching engine. Do not bid above that Law level merely because the opponents have pushed the auction higher.
Minor-suit versus NT preference: when game values are present and a minor fit is known, prefer 3NT to 5♣/5♦ whenever 3NT is legally available and the auction does not reveal an unstopped opponent suit. At invitational level, a balanced hand also prefers NT to committing to a minor. A minor contract remains the choice when NT is unsafe or unavailable.
Responder with support — use the better of points or LTC. For a major-suit fit with four or more trumps, compare the point-count raise (6–9 → 2-level, 10–12 → 3-level, 13+ → game) with the Losing Trick Count raise (9 losers → 2-level, 8 → 3-level, 7 or fewer → game) and make the higher bid. If the known combined trump holding is more than eight cards, deduct one loser before applying LTC. This allows distribution and a nine-card-or-better fit to upgrade the hand. With exactly three-card support, a marginal 9-loser hand may still make the simple raise to 2 of opener’s suit.
A four-card major is not suppressed when a one-level response is available. With 6–9 HCP and no three-card fit or better one-level suit response, 1NT remains the fallback response.
Stay low after a weak 1NT response: responder’s 1NT shows about 6–9 HCP. Opener does not rebid 2NT merely to describe a balanced hand. If even 9 opposite leaves the partnership below 25 HCP, pass 1NT; invite only when game is possible opposite the top of the range.
Pender–Flint after 1NT X: weak responder escapes by transferring so the 1NT opener remains declarer: XX → clubs, 2♣ → diamonds, 2♦ → hearts, 2♥ → spades. With no useful five-card escape suit, stay in 1NT X.
Stayman and transfers are completed: over 1NT, 2♣ is Stayman and 2♦/2♥ transfer to hearts/spades. Opener answers/completes; responder then signs off, invites or offers game. Over 2NT, 3♦/3♥ are transfers and 3♣ is Puppet Stayman, allowing opener to show a five-card major, a four-card major, or no major.
Strong 2♣: the auction is not allowed to die after the first response. With more than 4 HCP and an Ace, responder shows an Ace-control suit; 2♦ remains the waiting/negative response, so a diamond Ace control is encoded as 3♦ in this teaching version. Opener then rebids shape/NT and the partnership continues.
Fourth-suit forcing: once the partnership has naturally shown three suits, a game-going responder may bid the fourth suit artificially to keep the auction alive and ask opener for a stopper, delayed support or further shape.
Auction memory: a change of suit by responder is forcing for one round; fourth-suit forcing is forcing to game. The engine retains the strength promised by raises, negative doubles and NT rebids instead of judging each later call in isolation.
Slam tools: 4NT is quantitative in NT auctions, not Blackwood. Gerber is the slam-investigation convention: 4♣ asks for Aces (4♦ = 0/4, 4♥ = 1, 4♠ = 2, 4NT = 3); 5♣ asks for Kings with the same step pattern.
Suit-slam trigger: after a trump fit is established, opener compares their actual LTC with the assumed 7-loser opening hand. With 5 losers or fewer, combine opener's losers with the losers shown by responder's raise. If 18 minus that combined loser count suggests at least the five level, and 4♣ is still legally available, opener starts Gerber. LTC decides whether to investigate; Gerber decides whether enough top controls exist. Control cue-bidding is not used for slam investigation.
Negative doubles are used by responder after partner opens one of a suit and the next hand makes a natural suit overcall: normally 6+ HCP at the one level, 8+ at the two level, showing the unbid major(s).
A double of a weak 1NT is penalty with about 15+ HCP. Penalty doubles of suit contracts are reserved for higher-level contracts where the hand has real defensive values and/or a trump stack.
A redouble after an opponent's take-out double shows roughly 10+ HCP and strength; a redouble of a penalty double is used only with substantial confidence in the contract.
Double-dummy audit: after the Acol auction, DD is used only as a diagnostic. It can flag a contract that is down, or a possible missed game/slam, but it never replaces the information available to the bidders. “Sound” means the auction is consistent with the DD result; “Review” is a one-step warning; “Check bidding logic” is a larger discrepancy.
Paramount lead rule — choose the suit first, then the card. Against NT, partner's natural suit gets first consideration; otherwise choose from the auction and length. A sequence does not choose the suit — it only chooses the card after the suit has been selected.
NT — card from the selected suit: top of a sequence of three honours (or a near-sequence, e.g. AQJ); top of an internal sequence of three (or near-sequence, e.g. KJ108 → J); otherwise fourth from an honour when there is an entry to establish and cash the suit.
NT — small holdings: Middle-Up-Down from three small cards; top from a doubleton; the singleton from a singleton. The purpose of the long-suit lead is to drive out declarer's high cards, so an entry back to the hand matters.
Suit contract — “Should I lead a trump?” uses only the auction and the opening leader's own hand. Positive clues include delayed/reluctant trump agreement, a jump or competitive raise suggesting distribution, the declaring side bidding several suits before settling in trumps, outside honours sitting over a side suit they bid, and unattractive side-suit alternatives. Partner's clearly bid side suit, the other unbid major against an established major fit, or a useful singleton count against a trump lead. The test never looks at unseen dummy shape or the opponents' actual HCP.
If those clues do not justify a trump, choose the side suit first from the auction. Partner's suit has priority; when the opponents have found a fit in one major, prefer the other unbid major when available; then consider a useful shortage or another unbid/safe suit. Only after the suit is chosen does the engine apply sequence, A-K, doubleton or low-card rules. From three small cards in a safe suit, lead Middle-Up-Down (MUD): the middle card first.