This is a very controversial issue, because first you need to determine the real reasons for the player's unwillingness (or inability?) to finish the game. This is almost impossible to do. I see the solution in either agreeing on the game duration and completion time in the season rules, so that, for example, when the game (or completion) takes longer than the specified time (e.g., a month), a previously agreed-upon "judge" is called in to either determine who is at fault for the unfinished game and award the victory accordingly, or, if both players are equally at fault, make a decision. But this path seems tedious and unpromising to me. The option of simply not playing "friendly games" with such a player (unless the tournament bracket brings them together) is much simpler and does not bother anyone.