Dominoes / Strategy
Which domino should you open with?
If your table lets you choose the first tile, open with the double of your longest suit. It puts only one number on the table, it is a number you hold more of than anyone, and it leaves you the most tiles that can follow it. If you have no double in a long suit, lead a tile from that suit that keeps the most follow-ups in your hand. Leading your heaviest tile because it is heavy is a habit, not a strategy.
Before any of that, check whether you have a choice at all. In many traditions you do not.
Whether you get to choose
There is no governing body for dominoes, and the rule for the first tile is one of the places where tables disagree most. Here is what pagat.com, John McLeod's rules site, records:
| Tradition | First hand | Later hands |
|---|---|---|
| Block game (pagat main rules) | Draw for the lead, any tile | Lead passes to the left; one variation makes the highest double lead |
| Draw game (pagat main rules) | Draw for the lead, any tile | Lead passes to the left |
| Draw game, Puerto Rico | Holder of [6-6] leads it, or the highest double dealt | Winner of the last game leads |
| Partnership, Mexico and Colombia | Holder of [6-6] leads it | Winner of the last hand leads, any tile |
| Partnership, Venezuela | Holder of [6-6] leads it | Lead rotates, any tile (some tables: the winner leads) |
| Partnership, federation rules (FID) | Draw tiles for the lead, any tile | Lead rotates, any tile |
| Jamaican partner | Holder of [6-6] poses it | The winning team chooses which member poses, any tile |
Two more details. In Jamaican tournament play the [6-6] must be posed first; in informal games its holder may announce they are "sporting" and pose something else. And pagat's draw-game page lists tables that make every hand start with [6-6], drawing from the boneyard until someone finds it.
So in most partnership traditions the first hand of a match is decided for you. The choice arrives from the second hand on, usually for whoever won the last one. That is where the rest of this article applies.
What a first tile does
The first tile sets the two numbers everyone else must answer. A double sets one number on both ends. Any other tile sets two.
That is the whole argument for leading a double. Lead [4-6] and the next player can answer with any four or any six. Lead [4-4] and they need a four. Fewer tiles answer, so the next player is more likely to be stuck, and the number they are stuck on is yours.
The other half of the argument is what stays in your hand. Every tile carrying your number is a future turn where you can follow when others cannot. A double is also the hardest tile to get rid of later: it can only ever go on its own number. Lead it now and it can never be stranded in your hand.
The numbers behind it
Each number appears on seven tiles. In four-player partnership play all 28 are dealt, seven each, so 21 tiles are hidden from you and the next player — always an opponent — holds seven of them. The same arithmetic applies to two-player block with seven tiles each, where the other 14 sleep.
If you lead the double of a number and hold some of that number's other tiles, the rest are unseen. This is the exact chance the next player holds none of them and must pass:
| Tiles of the suit you hold, double included | Unseen tiles of the suit | Next player cannot answer |
|---|---|---|
| 2 | 5 | 9.8% |
| 3 | 4 | 16.7% |
| 4 | 3 | 27.4% |
| 5 | 2 | 43.3% |
Compare a non-double from a number you are weak in. Lead a bare [4-6] holding no other four and no other six, and twelve unseen tiles can answer. The chance the next player has none of them is 0.03%, about one deal in three thousand.
A Spanish-language guide to partnership play, based on Ignacio Zaibert's Conceptos y criterios del dominó por parejas, puts the threshold for a strong suit at four tiles; three gives some strength but not a majority. Its default opening is the highest double with the most companions. The table shows why four is the point where leading a suit starts to pay: more than one time in four the opponent who plays straight after you is already knocking.
A worked hand
You won the last hand and it is your lead. You hold:
[4-4] [4-1] [4-6] [4-0] [5-5] [5-2] [3-1]
| Lead | Numbers opened | Unseen tiles that answer | Next player cannot answer | Your tiles that can follow |
|---|---|---|---|---|
| [4-4] | 4 | 3 | 27.4% | 3 |
| [5-5] | 5 | 5 | 9.8% | 1 |
| [4-1] | 4 and 1 | 8 | 1.5% | 4 |
| [4-6] | 4 and 6 | 9 | 0.7% | 3 |
| [5-2] | 5 and 2 | 11 | 0.1% | 1 |
[4-4] is the clear lead. You hold four of the seven fours, the opponents get no second number to choose from, and you keep [4-1], [4-6] and [4-0] to put fours back on the line.
[5-5] is the tempting one: ten pips, and a double you may otherwise be stuck with. But you hold only one other five. Lead it and five unseen fives can answer, and you have spent your lead on a suit that belongs to someone else.
[4-1] keeps the most tiles that can follow, but it opens ones, and you hold only one other one. The double is still better: it commits the table to your number alone.
[5-2] is the worst lead in the hand. The Spanish guide calls a tile like this a fallo when you hold its numbers only once, and advises against playing one early, especially when you are the leader: it opens two numbers you cannot defend.
When your hand is weak
Some hands have no suit worth leading: three twos at most, no useful double. The same guide is blunt about this case. A leader with a poor or average hand should not try to take the initiative just because it is their turn; they should hand it to their partner as soon as they can.
In practice that means leading a tile that commits you to as little as possible, then watching your partner's first play and supporting it. The partnership guide covers what support looks like. In Jamaican partner play the question can be settled before the tile: the winning team may agree which member poses, as long as neither says what they hold. If your hand is the weaker one, let your partner pose.
How scoring changes the lead
The double-in-your-long-suit rule holds across most block and draw games. How much pip weight matters on top of it depends on how your table scores.
- Pip-scored games — North American block and draw, Mexican and Colombian partnership — make heavy tiles left in hand expensive. Between two leads of similar strength, take the heavier one. But in the hand above, [5-5] is only two pips heavier than [4-4]; control is worth far more than two pips.
- Jamaican partner scores one point per hand, to six-love. Pips decide only a blocked hand, so weight is almost irrelevant to the lead.
- All Fives scores the lead itself if the ends total a multiple of five: [5-5] and [6-4] score 10, [5-0], [4-1] and [3-2] score 5. The All Fives article works through why two ten-point leads are not equal: what the next player can score off your lead matters as much as what you score.
For more on the three systems, see how a domino game is scored.
What your lead tells your partner
In partnership play your first tile is also a message. Pagat's advice is that a partner should assume your lead is your strongest suit and play to it. If you lead from a weak suit, you send them the wrong way.
Whether partners may agree in advance what a lead means is a table question. The Spanish guide recommends agreeing on it, such as "my lead is my highest double with a companion", and notes that even a forced [6-6] can carry a signal through how quickly it is played. Jamaican partner play forbids talk and gestures about your tiles, though the speed of a play is considered fair to read. Ask before the first hand at a new table.
Something to try tonight
Before you lead, count how many tiles you hold of each number, and find the number where you hold four or more. If you hold its double, lead it. If you do not, lead the tile from it that leaves the most of that number in your hand. Then watch the next player: at four of a suit, they will be knocking more than one time in four.
The guide to what separates a good player from a lucky one shows how to keep counting that suit once it is on the table.