Given this tic-tac-toe position, as played by two expert players, who went first and where? Also, which was the last "move"?

 X | O | O 
---+---+---
   |   | X
---+---+---
   | X | O

(An expert player is a player who would never play in such a way that would allow his opponent to win, and who would also try to get the possible best result.)

I dont know about these players. But when I play and go second, I go in a square where there is no connection to the first player's move. That usually leave me with more possibilities.

With that assumption, top left (X), or bottom right (O) wouldnt be a possible choice for first move. Because the second move, which ever it may be, are placed in a line with the first move.

Anyway, here is my theory. O has to go first, cuz there is no connection what-so-ever for X. First player should have a 2 in a row at least once (if they are "expert player" and they have at least 1 opportunity and it also give them the advantage)

O went first

Couldnt be bottom right, cuz X wouldnt had go where ever he went cuz that would block up one of his/her possibilities.

Top middle's possibilities

1. O: top middle. X: top left. Illogical choice. Not only X is purposely getting block by O, O wouldnt have gone where he go in the second move, where ever that is

2. O: top middle. X: bottom middle. O: top right. X: top left. O: bottom right. X: middle right

Top right's possibilities

3: O top right. X top left. O would had gone middle right where s/he guarantee a win if s/he go in the middle after X has to block at bottom right

4: O: top right. X: middle right. O: top middle. X: Top left. O middle and guarantee a win where ever X gooes

5: O: top right. X: bottom middle. O: top middle. X:top left. O: bottom right. X: middle right

possibilities 2 and 5 are the only one that work now

2 is somewhat illogical because

a/ O's first move is at top middle, where s/he only has 2 way to win with that O (1 vertical and 1 horizontal)

b/ X's first move is at bottom middle, right in a line with O's first move. That eliminate his/her vertical win for that X. And middle would leave him/her only 1 way to win with that X (horizontal)

So, possibilities 5 is the best choice since a corner piece has 3 ways to win (1 vertical, 1 horz, and 1 diag). And O's third move cannot be place in the 2nd row (get nothing for left, middle would hand X the victory if he goes at bottom left, right would give X the upper hand)

In conclusion, O had the first move at top right and X had the last at middle right.

 

Random thoughts:

- 2 expert players playing tic-tac-toe would only prove who get tired and make the first mistake cuz if they (or so-so players) are in their right mind, all games would end in a tie.

- And (this is my own opinion) the best first move are placed in the middle where there are the best possibilities of a connection (4 actually, 1 vert, 1 horz, and 2 diag), whereas the corner only has 3 (1 vert, horz, and diag) and a middle of nowhere has 2 (1 vert and 1 horz). And not only that, it serves as the best blocking piece

Posted by elson on 2004-05-08 05:56:38