Determine Tic-Tac-Toe winner (round based)
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(.)(.)
$1O$2X
^
123;;456;;789¶X
{`(.)(.*¶)(.)\1
$3$2
}`.*(.)(.)*\1(?&lt;-2&gt;.)*(?(2)(?!))\1.*¶(..)*
$1$#3
.*¶
T
T`d`Rd


Try it online! Based on my answer to Tic-Tac-Toe - X or O?. Outputs X&lt;N&gt; if the first player wins after N turns, O&lt;N&gt; if the second player wins, T if neither wins. Explanation:

(.)(.)
$1O$2X
^
123;;456;;789¶X


Creates an internal board, and also marks each move with the player whose move it is.

{`(.)(.*¶)(.)\1
$3$2


Applies a move.

}`.*(.)(.)*\1(?&lt;-2&gt;.)*(?(2)(?!))\1.*¶(..)*
$1$#3


Searches for a win, and if one is found, then replace the board with the winner and the number of remaining moves.

.*¶
T


If the moves are exhausted and nobody has won then the game is a tie.

T`d`Rd


Calculate the number of the round from the number of remaining moves.