What's the current rule of chess regarding draws other than a stalemate or having a King bishop(or knight) vs lone King(automatic draw since they can't checkmate the king)?

Like when there's a threefold repetition, is that a mandatory draw or do at least one of the players must claim a draw?

What about the 50 move rule after there's only the King vs King + another piece(or more), if no one invokes these "rules", can the game go on forever?

I'm just wondering about whether there's a maximum theoretical number of moves in a game. People have said that it's 5949 moves, but I've never seen a proof of this and how they came to that number. How did they get that number and is it right?

tldr; if I didn't make sense up there, just wanted to talk about the maximum theoretical number of moves in a game and was wondering how the official draw rules affected that.

It seems about right that the maximum length of a game is 5949 moves. I'm assuming that it comes from the 50 move rule which states that there must be a pawn move or a capture in 50 moves otherwise the game is drawn.

So white has a maximum of 6 pawn moves (not 7 since the pawn starts on the second rank) for each pawn therefore he has 48 total pawn moves.

White also has 15 capturable pieces excluding the king obviously.

That is a total of 63 times that white can reset the 50 move rule counter.

Black also has these 63 options available as well so the maximum game length will be bounded by 63x50x2 which is 6300 moves.

Obviously the actual number will be less than that because the pawns can not continue to go forward without the opposition pawns being removed from its path. So there will be some form of a duplication counter reset where a pawn makes a move that is also a capture . It has to capture a piece because capturing an opposing pawn before it has a chance to make its moves to reset the counter would reduce the game length.

The 351 moves difference between the upper bound of 6300 and 5949, I am guessing is 7 times for a duplication counter reset and a single move loss for the transition when white resets the counter and then black resets the counter.

That seems to make sense in my head as I have not researched this or verified the quoted maximum length of 5949.

Isn't there also a mandatory draw when both sides have insufficient material? So you'd have to make sure that the last piece eliminated without before the 50-move limit would be a Q, R, or P.

Who cares? Its not like you're going to play a 6,000 move game in your lifetime...

"Like when there's a threefold repetition, is that a mandatory draw or do at least one of the players must claim a draw?"

In case of a threefold repetition or a 50-move-sequence without any captures or pawn moves, the draw needs to be claimed by one of the players.

If the same position occurs for the fifth time, or 75 consecutive moves have been made without a capture or pawn move, then the game is drawn automatically.

The theoretical limit has come into being because of FIDE's new 75 move rule. The 50 move rule allows for an astronomical number of moves.

The answer is 5898 1/2

To avoid misunderstandings: the rule 9.6 is for the arbiter not for the players.

For the players the rule is:

9.2 for same position 3 times

and 9.3 for the 50 moves without pawn movement or any capture.

The rule of 75 moves, or 5 repetitions of position, is made for the referee so that he can declare a draw even if the players have not agreed or didn't know they have done the 50 moves or the 3 times same position

Do promoting reset 50-move rule?

#8. Well, it's a pawn move...

I calculated 3670 moves until the 50 move rule has to be available.

Like @KasparovFan123 explained there are 63 reset options by moving pawns / capturing pieces. There is also a reset if a side loses the castling right. Each colour could lose 2 of them. 63+2=65 times 49 as the 50th move has to be the 1st on the next counter.

There is no need to capture pawns. He pawn can capture pieces to bypass other pawns.