How long can a player hold off a draw by the 50-move rule? Going by rules strictly about the board state, how long can a player theoretically hold off a draw by the 50-move rule? White will play as long as possible, and not want to lose. Black will claim a draw as soon as possible, if not win, so threefold repetition and dead position apply.
Here is my starting offer of 703 moves
[FEN &quot;5bkq/p1p1p1pR/P1P1P1P1/8/4K3/8/P1P1P2P/7n w - - 0 1&quot;]

1. Rxh8+ Kxh8 2. Kf3 Nf2 3. Kxf2

After taking 1 move to capture the queen and 2 for the Black knight,
White starts the 50-move reset counter. White shuffles around their
king to avoid repetition while Black's king is entombed. Every 50 moves thereafter, White plays a pawn move, with 12 total (playing h6 loses). After the 12th one, it will be another 50 moves until Black may rest: 1+2+50+(12*50)+50=704. (White's h-pawn position prevents dead position.)
The answer is trivially the starting position -
[fen &quot;&quot;]

This exact question hasn't been asked before (I think) but it has been answered here. Here is the relevant part of that answer -

The maximum number of moves in a chess game is not infinite, it's
11797 plies = 5898 moves and a half. This is due to the fifty-move
rule.

As an interim possibility here is an obvious extension of the OP's original position (before he made dozens of edits):
[FEN &quot;5b1k/p1p1p1p1/P1P1P1P1/8/8/8/P1P1P2P/RNBQKBNR w - - 0 1&quot;]

White makes the same starting pawn and king moves as in the OP's post minus allowing any captures and then brings a piece out to capture the a pawn, taking 49 moves to do that, then queens one of the a pawns taking 49 moves per pawn move, then takes 49 moves to sacrifice that queen next to the king, then same again with white's other a pawn, ditto taking the c pawn, etc., etc.