<p>My co-worker found what I believe is <a href="https://www.joachim-breitner.de/blog/archives/604-Ultimate-Tic-Tac-Toe-is-always-won-by-X.html" rel="noreferrer">a winning strategy for the first player</a>, but now I find <a href="https://www.khanacademy.org/cs/in-tic-tac-toe-ception-perfect/1681243068" rel="noreferrer">earlier evidence by others</a> as well.</p>

<p>This is for the original version of the game, where you can send your opponent to an already won field and he has to place his mark there. It seems that the question is still open for the updated version where he can then choose freely.</p>

CC BY-SA 3.0
2013-07-17T12:05:26.770Z
It looks like you've missed the clarification in the rules: "What if my opponent sends me to a board that’s already been won? In that case, congratulations – you get to go anywhere you like, on any of the other boards. (This means you should avoid sending your opponent to an already-won board!)"
tttppp
CC BY-SA 3.0
2013-07-17T12:07:14.417Z
(I've just seen that you've actually already fielded this point in the comments on your blog :-)
tttppp
CC BY-SA 3.0
2013-07-16T11:28:46.990Z
2013-07-17T12:16:24.560Z
2013-07-17T12:16:24.560Z
Joachim Breitner
<p><a href="http://mathwithbaddrawings.com/2013/06/16/ultimate-tic-tac-toe/" rel="noreferrer">Ultimate Tic Tac Toe</a> is an interesting variant of Tic Tac Toe where in each of the 9 fields, a “regular” game of Tic Tac Toe is played; see the link for details.</p>

<p>Has this game been solved already? Would it be possible to solve it using a brute force mini-max strategy?</p>

CC BY-SA 3.0
2013-07-15T13:48:14.970Z
There has been a discussion on [Hacker News](https://news.ycombinator.com/item?id=5898506), but nothing definite yet.
Joachim Breitner
CC BY-SA 3.0
2017-08-11T19:33:31.493Z
Great question!  I did some searching and found [this link from 2014 (redditt)](https://www.reddit.com/r/geek/comments/2ki98o/ultimate_tic_tac_toe/) that claims it has been solved.  Still trying to run down some corroboration, and will post if I find.
DukeZhou
<combinatorial-game-theory><tic-tac-toe><ultimate-tic-tac-toe>
Is Ultimate Tic Tac Toe solved?
Joachim Breitner
# Is Ultimate Tic Tac Toe solved?

(Asked by: username_0 on 2013-07-15)

[Ultimate Tic Tac Toe](http://mathwithbaddrawings.com/2013/06/16/ultimate-tic-tac-toe/) is an interesting variant of Tic Tac Toe where in each of the 9 fields, a “regular” game of Tic Tac Toe is played; see the link for details.

Has this game been solved already? Would it be possible to solve it using a brute force mini-max strategy?

**Tags:** combinatorial-game-theory, tic-tac-toe, ultimate-tic-tac-toe

> **Comments:**
> **username_0**: There has been a discussion on [Hacker News](https://news.ycombinator.com/item?id=5898506), but nothing definite yet.  
> **username_1**: Great question!  I did some searching and found [this link from 2014 (redditt)](https://www.reddit.com/r/geek/comments/2ki98o/ultimate_tic_tac_toe/) that claims it has been solved.  Still trying to run down some corroboration, and will post if I find.  

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## 1 answers

### Answer by username_0 on 2013-07-16. Score: 7

My co-worker found what I believe is [a winning strategy for the first player](https://www.username_0-username_0.de/blog/archives/604-Ultimate-Tic-Tac-Toe-is-always-won-by-X.html), but now I find [earlier evidence by others](https://www.khanacademy.org/cs/in-tic-tac-toe-ception-perfect/1681243068) as well.

This is for the original version of the game, where you can send your opponent to an already won field and he has to place his mark there. It seems that the question is still open for the updated version where he can then choose freely.

> **Comments:**
> **username_2**: It looks like you've missed the clarification in the rules: "What if my opponent sends me to a board that’s already been won? In that case, congratulations – you get to go anywhere you like, on any of the other boards. (This means you should avoid sending your opponent to an already-won board!)"  
> **username_2**: (I've just seen that you've actually already fielded this point in the comments on your blog :-)  

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