The Spinner in Dominoes: What It Is and How It Changes the Count
One bone in every hand gets to grow in four directions. Here's which one, when its arms open, how it counts at each stage, and why good players treat it like the center of the table.
Every hand of Fives has exactly one spinner, and it's usually the bone that decides how the hand goes. It sets the suit everyone has to work with, it's the only place the board can grow past two ends, and for a few turns it's the biggest number in the count. If you understand the spinner you understand the shape of the game. If you don't, you'll spend a lot of hands wondering where those points went.
Which bone is the spinner
The first double that hits the table in a hand. That's the whole definition. In the first hand of a game that's almost always the opening bone, because the first hand opens with the highest double whenever anybody holds one, and in a simulation we ran with the Cookout Dominoes engine that's 99.6% of first hands. In later hands the winner opens with whatever they like, and if it isn't a double, the spinner shows up whenever somebody plays the first one, on the third play or the ninth.
Lay it crossways: sideways to the direction the chain is running. That's not a style choice. It marks the spinner as the spinner, so nobody has to remember which double came first when there are three on the board.
When the arms open
The spinner's two long sides are open ends the moment it lands, like any other bone. Its top and bottom open only after both long sides have been played on. Not one side. Both. Until then the layout has the same two ends as any chain. After, it can have up to four, and that's where the big counts live.
Let's walk a hand with the 4-4 as the spinner and count at every stage.
Five stages, and the spinner itself was worth 8, then 8, then zero, zero, zero. That's the arc every spinner follows. It's loud for a couple of turns and then it's furniture, and the arms it opened are what matter for the rest of the hand.
A spinner in the middle of the hand
If the opener isn't a double, the chain runs for a while with no spinner at all. Then somebody plays one, and it becomes the spinner wherever it lands.
The other doubles are not spinners
This is where the variants diverge, so here's what we play and what other tables do:
| Game | Spinners | What it means for the board |
|---|---|---|
| Fives / All Fives (what the app plays) | First double only | At most four ends. Later doubles lie crossways, count both halves on an end, and you play off their sides only, matching their number. |
| Five-Up | Every double | The board branches at every double. Counts get huge and games run longer. Popular on the West Coast. |
| Muggins (strict, 1860s rulebook) | None | A straight chain with two ends the whole way. The original game the scoring family grew from. |
| Sniff | First double, with extras | Same single-spinner idea; some rulebooks let the sniff be laid lengthwise, which changes what it counts. |
One more thing that trips up people coming from block dominoes: in Fives a double on an end is not a dead end. You play off it normally, matching its number. It just counts both halves while it's sitting there. The full rules comparison is in Dominoes House Rules: 150 or 200?
Playing the spinner well
Its number is the hand's suit
Whatever the spinner is, that's the number the whole hand runs through. Every arm starts with it. If the 4-4 is the spinner, the 4s are the currency of the hand: whoever holds more of them controls more of the board, and whoever runs out first draws. There are only seven bones with a 4 on them, and the spinner is one, so six are in play. Count them. See How to Count Dominoes.
Opening its arms cuts both ways
Covering the spinner's second side opens two new ends. That's two more ways for you to score and two more ways to give. If you're ahead in the count and your hand is thin on the spinner's suit, there's a case for not being the one who buries it, because whoever plays the first arm usually gets first pick of the new geometry. If you hold three of the suit, bury it and go to work.
Every lonely double has one answer
While the spinner has an unplayed side it counts both halves, which makes the math for the other end very simple. Here's the bone that scores against each double when it's the spinner with one side played and nothing else on the far end:
| Spinner | Worth on its open side | Play this on the other end | Score |
|---|---|---|---|
| 0-0 | 0 | a 5 | 5 |
| 1-1 | 2 | a 3 | 5 |
| 2-2 | 4 | a 1, or a 6 | 5, or 10 |
| 3-3 | 6 | a 4 | 10 |
| 4-4 | 8 | a 2 | 10 |
| 5-5 | 10 | a blank | 10 |
| 6-6 | 12 | a 3 | 15 |
So when your opponent opens with the 6-6 and you're holding a 6-3, you're holding trees. And when you open with the 6-6, you've just told everyone what to look for. This is why the 5-5 is the best opener in the set and the 6-6 is only average, and why the heaviest bone isn't automatically the right lead. We tested every opener over 100,000 simulated hands in The Best Opening Domino, by the Numbers.
The spinner in the endgame
Late in a hand, the spinner's arms are usually where the last plays go, because they're the ends nobody has been working. If the boneyard is empty and you've counted the suit, you can often see exactly which arm your opponent can and can't reach. That's how blocked hands get engineered. See Blocked Dominoes: Who Wins and How It's Scored.
Questions people ask
What is the spinner in dominoes?
The first double played in a hand. It is laid crossways to the chain and is the only bone you can build off in all four directions: its two long sides right away, and its top and bottom once both long sides have been played on.
Is every double a spinner?
Not in Fives. Only the first double of the hand is the spinner. Later doubles still lie crossways and still count both halves when they sit on an end, but you cannot play off their top and bottom. In the Five-Up variant every double is a spinner; in strict Muggins there is no spinner at all.
When can you play off the top and bottom of the spinner?
Only after both of its long sides have been played on. Until then the layout has two ends. After, it can have up to four. The top and bottom join the score count only once a bone is actually placed on them.
Does the spinner count toward the score?
While it sits alone, yes, both halves. While one long side is played, its unplayed side still counts both halves. Once both long sides are covered it is inside the chain and counts nothing.
Can the spinner be played in the middle of a hand?
Yes. Whenever the first double of the hand lands, that double is the spinner, whether it opened the hand or came down on the eighth play. The side attached to the chain counts as already played; the outer side counts both halves until someone covers it.
Does a double block the end in Fives dominoes?
No. In Fives a double on an end is not a dead end; you play off it normally, matching its number. It just counts both halves while it sits there.