Dominoes / Rules
What happens when nobody can play? Blocked domino games explained
When nobody can play, the hand is over and it is decided on the tiles people are still holding. In almost every tradition the side with the fewest pips wins it. Where traditions part ways is on the details: whether the winner is one player or a team, whose pips get counted, and who takes the hand when the totals tie. There is also a piece of arithmetic worth knowing. In a game where every tile has been dealt, a block can only happen one way, which means you can see it coming and often name the exact tile that will cause it.
What counts as a block
A hand is blocked when no player can legally place a tile and nobody has gone out. In partnership play, pagat.com's comparison of the Latin American and federation rules describes it as four passes in a row with every player still holding at least one tile.
In draw games it takes longer to get there, because a player who cannot play has to draw first. In the draw rules John McLeod records at pagat, you draw until you can play or until only two tiles are left in the boneyard. The last two are never drawn. A hand blocks only when the boneyard is down to those two and still nobody can play. Pagat also notes that some Arabic-speaking tables stop at once, with no further drawing, as soon as the ends can no longer be matched.
Spanish-speaking players call a block a tranque or tranca, and closing the game on purpose is trancar.
A full deal can only block one way
In partnership dominoes with a double-six set, all 28 tiles are dealt, seven to each player. Nothing is left in a boneyard and nothing is out of play. That has a consequence most players have felt but never put into words.
Each number appears eight times in the set: once on each of the six tiles that pair it with another number, and twice on its double. Inside the line, matching halves always come in pairs. So if all seven tiles of a number are on the table, an even number of its eight halves must be sitting at the open ends. That is zero or two.
Put the other way round: in a full-deal game, a block requires both ends to show the same number, with all seven tiles of that number already played. If the two ends show different numbers, somebody at the table can still play. A paper by Carlos Parra and Eugenio Trucco of the Universidad Austral de Chile proves the same result for four-player partnership play, and adds that a block needs at least ten tiles on the table: the seven tiles of the blocking number and three others to link them.
This is why the habit of counting a suit pays off so directly here. A block is always the seventh tile of a suit.
Games with tiles left out work differently. In pagat's Block game, three or four players get five tiles each and the rest stay face down, unused. With eight to thirteen tiles out of play, a line can block with two different numbers at the ends, because the tiles that would have opened it are asleep. The article on luck at the table covers how those dead tiles change the odds.
Seeing it coming
Watch any number that is showing at an end and count how many of its tiles are down.
- Five down, one end showing it: two tiles of that number are left, and you know exactly which two. If one of them is in your hand, you already have a say in whether this hand blocks.
- Six down, one end showing it: one tile is left. If its other half matches the other end, whoever holds it can close the game by playing it there.
Worked example. The line runs, from one end to the other:
[4-1] [1-5] [5-4] [4-4] [4-0] [0-3] [3-4] [4-6] [6-2]
The open ends are 4 and 2. Six of the seven 4s are down; the only one missing is [4-2]. If you hold it and play it on the 2, both ends show 4, all eight 4-halves are on the table, and nobody can move. Ten tiles are down, which is the minimum the Chilean paper allows.
Whether you should play it depends on what you are left holding.
Should you close it?
Nine tiles are on the table before your play, so the board holds 66 pips once [4-2] goes down. The set has 168 in all. Subtract the board and your own hand, and you know exactly how many pips the other three players hold between them, even though you cannot see who holds what.
A light hand. Say that after playing [4-2] you hold [0-0] [1-2] [0-1] [2-3]: nine pips. The other three hold 93 pips in 14 tiles. Dealing those 14 tiles out at random, with your partner holding five and the opponents four and five, your team ends with fewer pips about 93% of the time and ties about 2% of the time. Under the Jamaican rule, where only the single lowest player counts, you cannot lose: the four lowest tiles still out add up to 12, so no opponent can get under your nine.
A heavy hand. Now say you are left with [6-6] [5-5] [6-5] [3-3]: 39 pips. The other three hold 63. Your team ends lighter less than 1% of the time on team totals, and wins about one time in five under the Jamaican rule. Closing here hands the game away; play elsewhere and keep the 2 end alive.
Those figures assume you know nothing else, and at a real table you do. Every pass tells you which numbers a player lacks, which shifts the odds. The point is the method: board, hand, set total, and you have the other side's pips in your head before you decide.
Who wins a blocked hand
Single players
In pagat's block and draw games for two to four players, each player counts their own pips and the lowest wins. In Block, the winner scores the losers' pips minus their own. If two players tie for lowest, nobody scores.
For draw games, pagat lists three ways tables settle a block, and the scoring article works through all three with the same hands: the winner takes everything left including their own pips, the others' pips minus their own, or the sum of the differences. Ties are settled by fewest tiles, or not at all.
Partnerships
Here traditions disagree on the most basic question: is it the team or a single player that wins?
- Latin American and federation rules: the team with the lower combined total wins. Pagat's table shows Mexico, Colombia and Venezuela scoring only the losing team's pips, and the federation rules (FID) and Puerto Rican Doscientos scoring all four hands.
- Jamaican partner: the hand goes to the team of the one player holding the fewest pips. Partners' totals do not count. Pagat's own example has a team win because one player is left with [1-1], although that team's combined total is higher.
- Milo, which pagat records from Africa and Indonesia: the lighter partnership scores one point for the round.
Pagat also records tables that do it differently again: the hand goes to the side that played first, to the side holding more tiles, or to the team that played the last tile. In one Puerto Rican variant, any block goes to whichever of the last player and the player to their right holds fewer points.
Ties
When the totals are equal, pagat's partnership table gives a different answer in each country:
| Tradition | Tied block goes to |
|---|---|
| Federation (FID) | Nobody; the next player starts |
| Mexico | The team that started the hand |
| Colombia | The team that blocked it |
| Venezuela | Nobody; the next player starts, or the holder of [6-6] |
| Puerto Rico, Doscientos | Nobody, or the team that played first, or the team that played last, depending on the group |
| Jamaican partner | Nobody, if the two lowest players are opponents; the holder of [6-6] poses next |
The Colombian rule changes strategy. If ties go to the blocker, closing on a level count is a win; under the Mexican rule, it hands the hand to the team that led. Know which table you are at before you play the seventh tile.
What to agree before you start
Three questions settle almost every blocked-hand argument:
- Team total or lowest single player? This decides whether a partner's heavy hand can sink you.
- Whose pips does the winner score? Losers only, or all four hands?
- Who takes a tie, and who leads next?
None of these has an official answer for a home game. Some tables also leave a small trap open: a player who turns their tiles face up, sure the game is blocked, when one more tile could still be played. In a full-deal game you can check before anyone does it. If the ends show different numbers, it is not blocked.