How to Run a Block Dominoes Tournament

A Block Dominoes tournament is a set of ordinary hands with three things added: a ruleset that is written down, a schedule that fixes how many hands each player gets, and a scoresheet that somebody other than the scorer can check. This article covers those three things and the disputes they prevent. The rules of the game itself are on the rules page and are not repeated here.

Write the ruleset down before anyone shuffles

The browser game on this site answers several questions silently, because the code has to pick something. At a live table those same questions get argued about, so each one needs a written answer that every player has seen before the first tile is turned over.

The opener. The highest double opens and must be played. If no double was dealt, the heaviest tile opens and its holder may play any tile. Write down that this applies to every hand of the match, not only the first. With four players all 28 tiles are dealt, so the 6-6 is always in somebody's hand and always opens. With two or three players, 14 or 7 tiles are set aside, so the 6-6 may be out of play and the opener is whatever double is highest among the tiles actually dealt.

The deal. Name who shuffles: the simplest rule is the player to the right of the previous hand's winner, so the duty moves round the table. Tiles are shuffled face down, each player takes seven without looking, and with two or three players the remainder is pushed aside face down. Say when those set-aside tiles may be turned up. Turning them up after the hand is scored settles any argument about where a missing double was, and costs nothing because they were never in play.

Blocked-hand ties. When nobody can play, the lowest pip total wins the hand. Two players can tie for lowest. The browser game gives the hand to whichever tied seat comes first in its turn order, which is acceptable for practice and not acceptable in a final. The two usual choices are worked through in the scorekeeping section below; pick one.

Match length and seat rotation. Both are covered in their own sections, because both involve arithmetic that decides how long the day runs.

Choosing a format, with the arithmetic

Single elimination. Every match removes exactly one player, so a field of N players needs N − 1 matches. Eight players need 7 matches: four quarter-finals, two semi-finals and a final, three rounds in all. Sixteen players need 15 matches over four rounds. A field that is not a power of two is padded with byes: twelve players become sixteen slots with four byes, still 11 matches, still four rounds. The cost is that half the field plays one match and is done.

Round robin. Everyone plays everyone, which is N(N − 1)/2 matches. Eight players need 8 × 7 / 2 = 28 matches, and each player plays 7 of them. With four two-player tables running at once that is 7 rounds. Six players need 15 matches in 5 rounds of 3. For the same eight people a round robin is four times the play of the bracket, and nobody goes home early.

Four-player tables. A Block hand at a four-seat table has one winner, so a table session sends one player of four forward. Sixteen players sit at four tables; the four table winners make the final table; that is 4 + 1 = 5 sessions in two rounds. Sixty-four players need 16 + 4 + 1 = 21 sessions in three rounds. Every entrant gets a full session of hands rather than a single match, which is the main reason to prefer it over a bracket when you have the tables.

How many hands is a match?

The winner of a hand scores the pips left in the other hands, and that number is not predictable. In a two-player hand it can be 0, if the loser is left holding only the 0-0. It cannot exceed the pips in the heaviest seven tiles of the set, which are 6-6, 6-5, 6-4, 5-5, 6-3, 5-4 and one of the 8-pip tiles: 12 + 11 + 10 + 10 + 9 + 9 + 8 = 69. So a two-player match to 100 points cannot finish in one hand, must take at least two, and has no upper limit at all, because a run of low-scoring hands can go on indefinitely. With four players three hands are counted, so single-hand scores run higher, but they vary just as much. A target score is a fine way to play; it is a poor way to fill a timetable.

For a scheduled event, fix the number of hands instead: four hands per session at a four-player table, which matches the rotation below, or six hands per two-player match. Highest total after the fixed hands wins; if the totals are level, one further hand decides it. Write both sentences down. To estimate the time per hand, play a few hands at your own table with the tiles you will use and a clock running. Do not take a figure from anywhere else, including this article, which does not give one.

Seating and rotation

At a two-player table the only thing to rotate is the shuffle, so alternate it. For four people at two-player tables a round robin is three rounds of two matches: A against B and C against D, then A against C and B against D, then A against D and B against C, six matches in all, with each player meeting each other player once.

At a four-player table the order of play matters. Play passes clockwise from the opener, so the player on your left answers your tile first and the player on your right sets the ends you see. Moving everyone one seat clockwise between hands changes nothing about that: the same person is still on your left. To vary the order you have to swap neighbours. The schedule below gives each player each seat exactly once over four hands, and every player is followed directly by every other player at least once. Three hands cannot manage that: there are twelve player-follows-player pairs to cover and three hands only supply twelve slots, and if you try every arrangement one pair always repeats.

Read the table by hand: in hand 1 player A is followed by B, in hand 2 by D, in hand 3 by C, and in hand 4 by B again. Every player has the same pattern, three different followers and one repeat, and every column contains each letter once. Print it on the scoresheet so nobody has to remember it.

Scorekeeping

A scoresheet that can be checked has a row per hand and, for each player, a column for pips left and a column for running total. The winner's score for the hand must equal the sum of the other pips-left entries in that row, so anyone can re-add the row later. Suppose player A goes out while B holds 6-4 and 3-3, C holds 5-2, and D holds 0-1 and 2-2. B's pips are 10 + 6 = 16, C's are 7, D's are 1 + 4 = 5, and A scores 16 + 7 + 5 = 28. The three losers read their pips aloud while their tiles are still face up, and only then are the tiles pushed in for the next shuffle. Mark a blocked hand with a B in the margin, because a blocked hand is where ties happen.

Two rules work for the tie in the figure. Under the first, the hand is void: nobody scores, the tiles are reshuffled, and the hand does not count toward a fixed-hand match, which the scorer must note. Under the second, each tied player scores the pips of the untied hands, so B and D each score 11 + 9 = 20 and A and C score nothing. For comparison, the browser game's built-in rule would give the whole hand to one of B or D, who would score 11 + 9 + 2 = 22 including the other tied hand. Any of the three is playable; only one of them may be on the sheet.

For an evening at home the same sheet can be simpler; the family play article covers that case.

Handling disputes

Name one referee on the scoresheet and make their decision final. If the referee is also playing, name a second person for the referee's own table. Then write down, in advance, what happens in each of the situations that actually come up:

• A dispute must be raised before the next tile is played. After that, the line stands as it is.
• A tile placed against an end it does not match, noticed in time, is taken back and a legal tile is played instead; if the player has none, they pass. Noticed too late, it stays, and play continues from the ends as they now are.
• A tile exposed during the shuffle or deal, or a player found with the wrong number of tiles before the opener is played, means a reshuffle and a fresh deal. Found after play has started, the hand is void and redealt.
• A player found to have passed while holding a tile that matched an open end has given every other player false information. The hand is void and redealt; a second offence forfeits the match.
• If you use a time limit per turn, say what happens when it runs out. A rule that needs no judgement is that the referee plays the first legal tile in the player's hand, which is exactly what the Easy computer opponent on this site does on every turn.

Everything above can be rehearsed in the browser before the event. Play four hands against the computer using Next hand rather than New Game, keep a paper scoresheet as you go, and check your running totals against the ones on screen after each hand. If they agree four times, your sheet layout is ready for a table of people.