Average defensive tricks
The primary ranking shows how many tricks the defense takes on average after each opening card.
Bridge SolverBest Lead
Opening Lead Analyzer for Contract Bridge
Compare plausible opening cards across deals that fit the known hand, auction and partnership assumptions. See which lead produces the most defensive tricks rather than judging from one fortunate layout.
Analyses require a Bridge Solver account.West♠ Q 8 5 2♥ K J 9♦ T 7 4♣ A 8 3
| Lead | Def. tricks | Declarer makes | Vs best |
|---|---|---|---|
| 2♠ | 4.31 | 58.2% | - |
| J♥ | 3.97 | 65.8% | -0.34 |
| 4♦ | 3.72 | 70.2% | -0.59 |
Workflow
How opening lead analysis works
An opening lead simulation separates the choice of card from the accidental layout at one table.
- 01
Enter the auction
Set the dealer and vulnerability, reproduce the calls, and confirm the final contract and declarer.
- 02
Enter the leader hand
Provide the opening leader’s exact 13 cards and add any descriptive conditions attached to that hand.
- 03
Constrain the unseen seats
Describe LHO, partner and RHO with points, suit lengths, known cards and auction-related filters.
- 04
Rank the lead cards
Generate matching deals, solve each candidate lead and compare its defensive results over the same distribution.
Output
What the opening lead analyzer measures
The strongest lead is the card with the best aggregate defensive performance in the modeled position.
Declarer make rate
See how often declarer reaches the contract target after a lead; the complement indicates how often the defense defeats it.
Difference from best
Alternatives are compared with the leading card in defensive tricks, making close choices easier to recognize.
Card-level ranking
Individual ranks are retained, so leading an honor and leading low from the same suit need not be treated as identical.
Generation diagnostics
Requested deals, accepted deals, attempts and pick rate expose whether the hidden-hand model produced a healthy sample.
Board inspection
Saved results let you inspect layouts where a lead gains or loses instead of stopping at the average.
Example
Attacking or passive against 3NT?
West is on lead against 3NT. A spade lead may establish the long suit, while a passive club or diamond may avoid giving declarer an immediate trick.
Model what the auction says
Enter West’s exact hand, then describe North, East and South from the auction. If North showed a five-card major, give that seat the appropriate suit minimum. If East could not act over a strong notrump, test a realistic point ceiling rather than leaving every hand equally likely. A lead is only as good as the layouts against which it is being measured.
The result may show that the attacking spade lead defeats more contracts, even though it occasionally gives declarer a cheap trick. Or a passive lead may win because the auction makes partner unlikely to hold an entry. Inspecting the boards where the top two cards disagree explains the mechanism behind the average.
Interpretation
Read the size of the edge
Start with average defensive tricks and declarer make percentage. If two cards differ by only a few hundredths of a trick over a modest sample, the practical conclusion may be that the choice is close. A larger difference that persists when you widen or narrow the auction constraints is stronger evidence.
The current Best Lead result does not present an IMP ranking for every lead. Avoid translating a trick difference into an invented IMP claim. Instead, inspect how often the contract is made, how often it is beaten and which classes of layout create the gain.
Questions worth asking
- Is the gain concentrated in one unlikely partner holding?
- Does the lead still win if an opponent’s range changes?
- Are two spot-card leads effectively equivalent?
- Would the double-dummy continuation be findable at the table?
Methodology
Double dummy is powerful, with limits
For every accepted hidden layout, double-dummy analysis sees all four hands and finds best play after the opening lead. That creates a consistent comparison and prevents one candidate from receiving a weaker continuation by accident. It also gives defenders information they would not possess in real play.
Real partnerships have signaling agreements, defensive habits and different abilities to find switches. The analyzer does not model those human factors. Use it to understand the technical potential and layout sensitivity of each lead, then apply partnership and field judgment separately.
Questions
Opening lead analyzer FAQ
How does Bridge Solver choose the best opening lead?
It generates deals consistent with the opening hand, auction and hidden-hand constraints, tests legal lead cards with double-dummy analysis, and ranks them primarily by average defensive tricks over the accepted deals.
Does the analyzer understand the auction?
The Best Lead workflow includes an auction editor with dealer, vulnerability and declarer. The auction determines the contract and opening leader, while you explicitly describe the hand ranges and shapes implied by the calls.
What does declarer make percentage mean?
It is the percentage of analyzed deals on which declarer makes the contract after that opening lead under double-dummy play. Contract defeat rate is the complementary percentage when every deal has a solved outcome.
Will the top lead always be best at the table?
No. The ranking depends on the generated hand distribution and double-dummy continuation. Human defenders do not see all four hands, and a lead that is technically best may create a continuation that is difficult to find in practice.
Can I compare specific cards from the same suit?
Yes. Results rank individual opening cards, so leads such as a low spot, an honor or the top of a sequence can have separate outcomes when the analysis distinguishes them.
Keep exploring
Related bridge analysis tools
Run your own analysis
Test the lead, not just the result
Enter the auction and opening hand, describe the unseen seats, and compare the legal lead cards over matching deals.