Longest non-cooperative game of chess Typical arguments for the longest possible game of chess take a form something like this.

1) Each player moves their knights back of forth 49 times
2) Each player moves one pawn forward one square and repeats the knight shuffling.
3) Once all pawns are on the 4th and 5th ranks, ....
and so on. 

I,we found estimates around 9000. I'm interested in the longest possible game of chess, with the restriction that the players are actually trying to win, and not cooperating to make the longest possible game allowable by the rules. We might call this the longest realistic game of chess.

Since the above argument totally breaks down, what are some new considerations that might allow us to lower the upper bound on the longest realistic game of chess?
The longest game I've ever found in tournament play is Nikolic - Arsovic, played in Belgrade in 1989. You can watch it here. It ended in a draw after 269 moves in a rook+bishop-vs-rook endgame