Master your opening leads
Practice on hands the robot deals — or analyze the one you just played. Every lead, ranked across thousands of simulated deals.
Practice: every deal freshly generated — no two players ever see the same hand. Beginner hands — free and unlimited. Subscribers unlock every difficulty, deeper simulations, and the practice filters.
1-week free trial · then $5.99/mo or $49.99/yr · Get a license key
1 Opening lead hand
Enter the hand you’ll lead from — or import it below.
Mobile: take the screenshot in BBO, select the button, then pick the image. The BBO app tends to log you out when you switch away — play at bridgebase.com in your phone’s browser instead, which doesn’t.
Desktop: snip with Win+Shift+S / ⌘⇧4, then the desktop button — or just press Ctrl+V anywhere.
The shot must show the auction panel from its first call (scroll it to the top) and your 13 cards — the card fan or the text list, with your gold name bar. Portrait or landscape both work; the rest of the screen doesn’t matter.
Works for any board you’ve finished — the deal comes straight from BBO, so nothing is guessed at.
If what you get is a short tinyurl.bridgebase.com/… address, open it in your browser first, let it redirect, then copy the long …handviewer.html?lin=… address out of the address bar and paste that.
Still playing the board? Nothing has been recorded yet — use Import from screenshot instead.
2 The contract
Which contract are you defending against?
3 Auction inferences
Constrain hands based on the bidding.
Commas mean and; OR gives alternatives.
15+ or -7s h d c, chain several5=4=3=1 works too)4 Simulate hands
Decide how many deals to simulate.
Results
Lead ranking
| Lead | Beats contract | Avg tricks |
|---|
Simulation analysis
Browse the simulated deals — pick a lead to sort the deals it wins to the top.
Set up a hand and run a simulation.
A worked example is loaded. Press Start to see which lead wins.
Your lead
Verdict
| Lead | Beats contract | Avg tricks |
|---|
Nothing selected = anything goes. Filters apply to the next deal.
Filters are part of the subscription — free play deals unlimited beginner hands.
Two tools in one. Practice: the robot deals and bids all four seats, you pick your opening lead, and a simulation of thousands of layouts grades it. Analyze: enter or import a hand you actually led from, and every lead is ranked by how often it beats the contract across deals consistent with the auction.
Press Next hand. The robot deals at random and bids all four seats; when the auction lands somewhere the opening lead genuinely matters, you're put on lead. Pick a card and the simulator deals thousands of layouts consistent with that auction, solves each one double-dummy, and tells you whether your lead was right — with the full evidence to browse. Difficulty reflects how clear-cut the winning lead is. Beginner hands are free and unlimited; the subscription unlocks intermediate through expert.
Your 13 cards are fixed and the other 39 are dealt at random, then filtered so every accepted deal matches the constraints implied by the auction — point ranges, suit lengths, and on common sequences the inferences from bids not made (after 1NT-2♣-2♦, declarer is capped at three cards in each major). Each accepted deal is solved with the DDS double-dummy solver. The verdict reports each lead's beat percentage and average tricks with a confidence interval, and only calls a winner “clear” when the paired difference is statistically solid.
Double-dummy means both sides play perfectly seeing all 52 cards after the lead — the research standard used by opening-lead books, with a known caveat: it slightly flatters attacking honour leads and undervalues passive or deceptive ones, because declarer never misguesses. We say so under every result. Real tables add human error on both sides.
Free: unlimited beginner practice hands, plus the analyzer with manual hand entry, basic constraints, 100-deal simulations and the headline verdict. The subscription ($5.99/month or $49.99/year, 7-day free trial) adds every difficulty from intermediate to expert, the practice filters (contracts, difficulty, auction type), BBO screenshot and Handviewer-link import, auction-driven constraint autofill, granular constraint clauses, the full ranked table of every lead, a deal-by-deal browser, and simulations up to 5,000 deals. Checkout is handled by Lemon Squeezy, which takes care of VAT and invoicing for EU and international customers.
Yes. Subscribers can import the hand on lead from a BBO screenshot (phone or desktop) or from a BBO Handviewer link for any finished board — the deal comes straight from BBO, so nothing is retyped.
No. It's a web app that runs in the browser on your phone, tablet, or computer — nothing to download, and the free tier needs no account. On a phone, your browser's “Add to Home Screen” installs it like an app.
I’m Jorrit Schäfer. I played junior international bridge for Belgium from 2008 — including three European Youth Championships — and founded the Imperial College London bridge club, captaining it to the UK university title (the Portland Bowl) in 2013 and to second place in 2010 and 2014. Professionally I took a PhD in bioinformatics, analysing RNA-sequencing and other large genomic datasets, and I now work as a director of advanced analytics in the pharmaceutical industry, helping teams make data-driven decisions. Killer Bridge Leads exists for two reasons: opening leads were the part of the game where everyone — me included — was going in mostly blind, with no way to quantify how much one lead was worth over another; and there was no dedicated, effective tool for actually training them. Now there is. You can find me on LinkedIn.
The bidding is powered by EPBot / BBA, created by Edward Piwowar and used here with his kind permission. The double-dummy card-play mathematics come from DDS, Bo Haglund’s open-source solver. Killer Bridge Leads puts their engines to work on the opening-lead problem — our thanks to both.
Hands never leave your device: dealing, bidding, and double-dummy solving run entirely in your browser. The only network calls are the license check and checkout.
Club and tournament players who want to check their opening leads against the evidence, teachers building lead problems for classes, and anyone who has ever lost a postmortem argument about a lead.