<p>D3C5D6E3B4C3D2C4F4 which is the same sequence Julia gave, not only answers the bonus question, but actually all questions. The least number for both players to not have an option is the 9 move wipe out, so 13 discs including the starting discs. It also is the answer to the first question, unless you want to say "one player of the two players can't make a move but the other can". In that case the sequence would be quite a bit longer. I remember someone posting a sequence to a very early pass and if I recall correctly the pass was in the early 20's.</p>

CC BY-SA 4.0
2018-11-09T00:28:18.347Z
2018-11-11T21:10:31.937Z
2018-11-11T21:10:31.937Z
Matthias Berg
<p>For the bonus, the shortest possible game that results in all pieces the same colour (9 moves) is here: <a href="https://www.youtube.com/watch?v=6ehiWOSp_wk" rel="noreferrer">https://www.youtube.com/watch?v=6ehiWOSp_wk</a></p>

CC BY-SA 3.0
2017-11-25T19:42:41.883Z
2017-11-25T19:42:41.883Z
Julia Hayward
<p>Say you're following the traditional rules of Othello. What is the least number of pieces possible on the board, producing a result where one of the two players(black or white) can't make a move, thereby passing play to the other player?</p>

<p>What is the least number of possible pieces on the board where both players can't make a move, therefore ending the game before the grid is completely filled?</p>

<p>Bonus question: An othello game can end with the board being entirely filled all one color. Is it possible for all the pieces on an Othello board to be one color, but the board isn't filled entirely? If so, can you give a sequence of moves that would result in that outcome?</p>

CC BY-SA 3.0
2017-11-19T10:03:38.667Z
For the first question, does it need to be a situation that can arise in a real game of Othello or we can just lay the pieces however we want to set up that situation?
Hai
CC BY-SA 3.0
2017-11-19T16:53:24.507Z
It has to arise out in a real game of othello. Same with the second question.
Mrcitrusboots
CC BY-SA 3.0
2017-11-19T21:50:00.460Z
Otherwise the problem would be ridiculously easy.
Arcanist Lupus
CC BY-SA 3.0
2017-11-21T21:13:23.200Z
Interesting question!  Related: https://boardgames.stackexchange.com/questions/20539/is-it-possible-for-an-othello-reversi-game-to-end-without-the-board-being-fill
DukeZhou
CC BY-SA 3.0
2017-11-24T14:27:52.973Z
I think "fewest number" is more appropriate than "least amount."
sirjonsnow
CC BY-SA 4.0
2018-12-16T23:59:49.537Z
@sirjonsnow: I find “fewest number” unidiomatic (and I am even uneasy about “least number”, in spite of “this number is less than that”), but I find “smallest” or “lowest number” fine.
PJTraill
<game-design><othello><combinatorial-game-theory>
What's the least amount of pieces on an Othello board where black or white can't make a move?
Mrcitrusboots
# What's the least amount of pieces on an Othello board where black or white can't make a move?

(Asked by: username_0 on 2017-11-19)

Say you're following the traditional rules of Othello. What is the least number of pieces possible on the board, producing a result where one of the two players(black or white) can't make a move, thereby passing play to the other player?

What is the least number of possible pieces on the board where both players can't make a move, therefore ending the game before the grid is completely filled?

Bonus question: An othello game can end with the board being entirely filled all one color. Is it possible for all the pieces on an Othello board to be one color, but the board isn't filled entirely? If so, can you give a sequence of moves that would result in that outcome?

**Tags:** game-design, othello, combinatorial-game-theory

> **Comments:**
> **username_1**: For the first question, does it need to be a situation that can arise in a real game of Othello or we can just lay the pieces however we want to set up that situation?  
> **username_0**: It has to arise out in a real game of othello. Same with the second question.  
> **username_2**: Otherwise the problem would be ridiculously easy.  
> **username_3**: Interesting question!  Related: https://boardgames.stackexchange.com/questions/20539/is-it-possible-for-an-othello-reversi-game-to-end-without-the-board-being-fill  
> **username_4**: I think "fewest number" is more appropriate than "least amount."  
> **username_5**: @username_4: I find “fewest number” unidiomatic (and I am even uneasy about “least number”, in spite of “this number is less than that”), but I find “smallest” or “lowest number” fine.  

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## 2 answers

### Answer by username_6 on 2018-11-09. Score: 3 | Accepted answer

D3C5D6E3B4C3D2C4F4 which is the same sequence Julia gave, not only answers the bonus question, but actually all questions. The least number for both players to not have an option is the 9 move wipe out, so 13 discs including the starting discs. It also is the answer to the first question, unless you want to say "one player of the two players can't make a move but the other can". In that case the sequence would be quite a bit longer. I remember someone posting a sequence to a very early pass and if I recall correctly the pass was in the early 20's.


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### Answer by username_7 on 2017-11-25. Score: 5

For the bonus, the shortest possible game that results in all pieces the same colour (9 moves) is here: <https://www.youtube.com/watch?v=6ehiWOSp_wk>


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