Will a decoder-only transformer also work? (Was: Spring 2025 Challenge: TicTacToe Transformer)

Ok, my bad. You can of course also try a decoder-only.
Just like here in this Python code example:
 > **Simple PyTorch Implementation of “Grokking”**
 > We trained a standard decoder-only transformer (Vaswani et al., 2017)
 > https://github.com/teddykoker/grokking
The transformer need not necessarely have a encoder and
a latent space. It can be also a decoder-only.
Mild Shock schrieb:

 Very simple challenge conceptually, develop the idea
of Centipawn towards TicTacToe and implement the
game based on learning / training a transformer, and
 then executing it. All written in Prolog itself! Optional
bonus exercise, make the execution ИИUƎ style, i.e.
incremental evaluation of the transformer.
 Centipawn - Chess Wiki
https://chess.fandom.com/wiki/Centipawn
 NNUE - Chess Programming Wiki
https://www.chessprogramming.org/NNUE