- 11 Nov '04 13:42

What is the 50 moves rule?*Originally posted by thire***How long is the longest possible chessgame?**

Please have in mind that a 3fold repetion ends the game, as well as the 50-moves rule.

th

hint: it is a finite number: all possible chesspositions are finite and every position can just occur 2 times... - 11 Nov '04 14:20 / 1 editAre you still aiming to win the game?

If not, then because the repetition rule is only for concurrent repetitions, if we take all the pawns into a zigzag stalemate and then both players continue to move their knights back and forthe one after the other, or incorporate a third piece such as a bishop into the mix for flavour, then it is possible to make the game last eternally. No concurrent repetitions need occurr.

If on the other hand you are saying that no three "entire board positions" are repeatable, then the number is somewhere in the region (i'm guessing here, feel free to correct) of 32 (number of pieces) to the power of 64 (squares on the board) x 2 for repetitions, minus whatever numbers are apparent during the taking of pieces. I cannot (with my limited intellect) even begin to calculate the possible differences in moves that would influence these numbers so I guess all i can say is that it is less than 4.27197 to the power of 96, a sum that made my calculator lag

Someone who actually understands these things will now prove me a simpleton, I look forward to your enlightening me - 11 Nov '04 20:45 / 1 edit

We must avoid a draw by the 50 move rule, therefore we must have a piece capture, or a pawn move by either side, on move 50*Originally posted by thire***How long is the longest possible chessgame?**

Please have in mind that a 3fold repetion ends the game, as well as the 50-moves rule.

th

hint: it is a finite number: all possible chesspositions are finite and every position can just occur 2 times...

The general plan is that each side hops their knights around without hitting the same position for 49 1/2 moves, them someone moves a pawn etc. We must also try to rarely capture pieces with pawns (some pawn piece capture's are necessary to get the pawns past each other to queen), and we must never capture pawns because once they queen they give us a whole piece more to do 50 moves with.

Considering only white. his pawns can each make 7 moves, queening on the seventh move, and 4 of those pawn moves must be captures to get his pawns past blacks. He has 15 black pieces to capture so he has 11 captures which aren't also pawn moves. That gives him 8*7+11 = 67 "50 move rule reset" moves. We also want to avoind switching resetting between black and white too much - because each switch costs us half a move.

so the general plan is

A) after 50 moves, Black moves a pawn to free his bishop, queen and two knights. we are on move 50

B) sort out white's pawns - white captures black's bishop, queen and knights with pawns to get his pawns into a configuration where black's pawns can pass, now we are on move 249 1/2

C) black makes 7 piece captures and his 55 remaining pawn moves, 4 piece captures are also pawn moves so that's 58*50 - 1/2 = 2899 1/2 more moves - putting us on move 3149

D) white makes his remaining 11 captures and 52 pawn moves leaving black with a king only - putting us on move 6298 1/2

E) black captures white's remaining 8 pieces, with his king putting us on move 6698

F) The players shuffle their kings around for 50 more moves, ending with a draw by the 50 move rule on move 6748

I'm pretty sure I've missed some things there, and that number is either a bit too big or a bit too small, any improvments on that folks?

EDIT: Doh - there is a huge mistake there - pawns can only do 6 moves without queening! - 12 Nov '04 01:19In fact chess game may go on forever.

Offical FIDE rules (www.fide.com) state that:

"The game is drawn, upon a correct claim by the player having the move, if the last 50 consecutive moves have been made by each player without the movement of any pawn and without the capture of any piece."

The point is that player CAN (not MUST) claim a draw. So, strictly speaking, chess game is infinite. - 12 Nov '04 03:05Of course you have to admitt that the game has to be ended as soon this is possible according to the rules (if someone can claim the 50-moves rule to end the game, he has to), and that the question makes sense we will exclude the option of resigning

I think iamatiger is on the right way, but the I get a different result (a try here):

lets say that you are inventive enough to avoid the end of the game by the repetition rule (concurent repetitions or other never mind), then the limiting facter is the 50moves rule. So, as said by iamatiger we need either a pawn move or a capture to have a "reset move".

We find a maximum of 6*8 pawn moves on each side giving 96, and beeing able to capture anything except the kings we can have 30 captures. we can find therefore an upper bound: 99*(96+30)=12474 halfmoves or 6237 entire moves.

The king shuffle game adds another 99 halfmoves. At least one halfmove is lost lost during "resetmove color switching" (the 98th halfmove instead of the 99th resetmove must occur) and white has to begin (we don't want to lose a precious halfmove already at the beginning, do we?)

Leaves 6236,5 moves max.

a question is how we should manouver our pawns past the enemy pawn line - remember, if a pawn is lost, you lose all the resetmoves connected

to him too!

if the color is not switched (in terms of resetmoves) more than once this would be impossible - a black pawn must be captured in order to give the white ones a breach where to get through! so the art is manouvering the pawns through enemy lines without:

a) capturing pawns

b) switching colors as seldom as possible

I count the following color switches (of cours do your fillingmoves in between):

bringing the white pawns in position: 0

then the black ones: 1

get the first 4 white ones behind enemy lines (4 black pieces are captured = takes 4 resetmoves away, because a pawnresetmove and a capture move are the same here!): 1

now the now you switch and command 4 black pawns behind the opposing 4 white pawns (which are still in the line of advancement).:1

all pawns are free now, (another 4 pieces are captured by pawns) and we continue with the black pawns to promote them.

we switch again to white, making the last pawn moves and blasting any enemy pieces out of existance (just let the king live): 1

the black king naturally takes vengeance and does the same with white:1

kingshuffling:0

takes in all 5 color switchings and 8*99(=792) halfmoves (for the pawns capturing pieces), thus leaving me with a funny calculation and a result of 11677 halfmoves, with the black king making the last move in the 5839th move in the game.

- 12 Nov '04 19:17 / 2 editsThe longest possible game, under current FIDE rules would result in a possible 5,949 moves, although I think technically the 50-move rule can be extended to 100 moves; so theorectically the longest legal game could last for 5,999 moves.

*Originally posted by thire***And which is the longest two GMs played?**

th

AFAIK, the longest GM game ever played is Nilolic - Arsovic, 1989, in Belgrade. A 269-move draw in about 20 hours! - 12 Nov '04 21:50thanks.

I searched for these guys and found these pages:

http://www.chess-poster.com/english/notes_and_facts/did_you_know.htm

http://www.xs4all.nl/~timkr/records/records.htm

th

the game....

Nikolic,I vs. Arsovic

Belgrade 1989

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 Nbd7 7.O-O e5 8.Re1 Re8 9.Bf1 h6 10.d5 Nh7 11.Rb1 f5 12.Nd2 f4 13.b4 g5 14.Nb3 Bf8 15.Be2 Ndf6 16.c5 g4 17.cxd6 cxd6 18.a3 Ng5 19.Bf1 Re7 20.Qd3 Rg7 21.Kh1 Qe8 22.Nd2 g3 23.fxg3 fxg3 24.Qxg3 Nh3 25.Qf3 Qg6 26.Nc4 Bd7 27.Bd3 Ng5 28.Bxg5 Qxg5 29.Ne3 Re8 30.Ne2 Be7 31.Rbd1 Rf8 32.Nf5 Ng4 33.Neg3 h5 34.Kg1 h4 35.Qxg4 Qxg4 36.Nh6 Kh7 37.Nxg4 hxg3 38.Ne3 gxh2 39.Kxh2 Rh8 40.Rh1 Kg6 41.Kg1 Rc8 42.Be2 Rc3 43.Rd3 Rc1 44.Nf1 Bd8 45.Rh8 Bb6 46.Kh2 Rh7 47.Rxh7 Kxh7 48.Nd2 Bg1 49.Kh1 Bd4 50.Nf1 Bg4 51.Bxg4 Rxf1 52.Kh2 Bg1 53.Kh3 Re1 54.Bf5 Kh6 55.Kg4 Re3 56.Rd1 Bh2 57.Rh1 Rg3 58.Kh4 Rxg2 59.Kh3 Rg3 60.Kxh2 Rxa3 61.Rg1 Ra6 62.Rg6 Kh5 63.Kg3 Rb6 64.Rg7 Rxb4 65.Bc8 a5 66.Bxb7 a4 67.Bc6 a3 68.Ra7 Rb3 69.Kf2 Kg5 70.Ke2 Kf4 71.Ra4 Rh3 72.Kd2 a2 73.Bb5 Rh1 74.Rxa2 Rh2 75.Be2 Kxe4 76.Ra5 Kd4 77.Ke1 Rh1 78.Kf2 Rc1 79.Bg4 Rc2 80.Ke1 e4 81.Be6 Ke5 82.Bg8 Rc8 83.Bf7 Rc7 84.Be6 Rc2 85.Ra8 Rb2 86.Ra6 Rg2 87.Kd1 Rb2 88.Ra5 Rg2 89.Bd7 Rh2 90.Bc6 Kf4 91.Ra8 e3 92.Re8 Kf3 93.Rf8 Ke4 94.Rf6 Kd3 95.Bb5 Kd4 96.Rf5 Rh1 97.Ke2 Rh2 98.Kd1 Rh1 99.Kc2 Rh2 100.Kc1 Rh1 101.Kc2 Rh2 102.Kd1 Rh1 103.Ke2 Rh2 104.Kf1 Rb2 105.Be2 Ke4 106.Rh5 Rb1 107.Kg2 Rb2 108.Rh4 Kxd5 109.Kf3 Kc5 110.Kxe3 Rb3 111.Bd3 d5 112.Rh8 Ra3 113.Re8 Kd6 114.Kd4 Ra4 115.Kc3 Ra3 116.Kd4 Ra4 117.Ke3 Ra3 118.Rh8 Ke5 119.Rh5 Kd6 120.Rg5 Rb3 121.Kd2 Rb8 122.Bf1 Re8 123.Kd3 Re5 124.Rg8 Rh5 125.Bg2 Kc5 126.Rf8 Rh6 127.Bf3 Rd6 128.Re8 Rc6 129.Ra8 Rb6 130.Rd8 Rd6 131.Rf8 Ra6 132.Rf5 Rd6 133.Kc3 Rd8 134.Rg5 Rd6 135.Rh5 Rd8 136.Rf5 Rd6 137.Rf8 Ra6 138.Re8 Rc6 139.Ra8 Rb6 140.Ra5 Rb5 141.Ra1 Rb8 142.Rd1 Rd8 143.Rd2 Rd7 144.Bg2 Rd8 145.Kd3 Ra8 146.Ke3 Re8 147.Kd3 Ra8 148.Kc3 Rd8 149.Bf3 Rd7 150.Kd3 Ra7 151.Bg2 Ra8 152.Rc2 Kd6 153.Rc3 Ra2 154.Bf3 Ra8 155.Rb3 Ra5 156.Ke3 Ke5 157.Rd3 Rb5 158.Kd2 Rc5 159.Bg2 Ra5 160.Bf3 Rc5 161.Bd1 Rc8 162.Bb3 Rc5 163.Rh3 Kf4 164.Kd3 Ke5 165.Rh5 Kf4 166.Kd4 Rb5 167.Bxd5 Rb4 168.Bc4 Ra4 169.Rh7 Kg5 170.Rf7 Kg6 171.Rf1 Kg5 172.Kc5 Ra5 173.Kc6 Ra4 174.Bd5 Rf4 175.Re1 Rf6 176.Kc5 Rf5 177.Kd4 Kf6 178.Re6 Kg5 179.Be4 Rf6 180.Re8 Kf4 181.Rh8 Rd6 182.Bd5 Rf6 183.Rh1 Kf5 184.Be4 Ke6 185.Ra1 Kd6 186.Ra5 Re6 187.Bf5 Re1 188.Ra6 Ke7 189.Be4 Rc1 190.Ke5 Rc5 191.Bd5 Rc7 192.Rg6 Rd7 193.Rh6 Kd8 194.Be6 Rd2 195.Rh7 Ke8 196.Kf6 Kd8 197.Ke5 Rd1 198.Bd5 Ke8 199.Kd6 Kf8 200.Rf7 Ke8 201.Rg7 Rf1 202.Rg8 Rf8 203.Rg7 Rf6 204.Be6 Rf2 205.Bd5 Rf6 206.Ke5 Rf1 207.Kd6 Rf6 208.Be6 Rf2 209.Ra7 Kf8 210.Rc7 Rd2 211.Ke5 Ke8 212.Kf6 Rf2 213.Bf5 Rd2 214.Rc1 Rd6 215.Be6 Rd2 216.Rh1 Kd8 217.Rh7 Rd1 218.Rg7 Rd2 219.Rg8 Kc7 220.Rc8 Kb6 221.Ke5 Kb7 222.Rc3 Kb6 223.Bd5 Rh2 224.Kd6 Rh6 225.Be6 Rh5 226.Ra3 Ra5 227.Rg3 Rh5 228.Rg2 Ka5 229.Rg3 Kb6 230.Rg4 Rb5 231.Bd5 Rc5 232.Rg8 Rc2 233.Rb8 Ka5 234.Bb3 Rc3 235.Kd5 Rc7 236.Kd4 Rd7 237.Bd5 Re7 238.Rb2 Re8 239.Rb7 Ka6 240.Rb1 Ka5 241.Bc4 Rd8 242.Kc3 Rh8 243.Rb5 Ka4 244.Rb6 Rh3 245.Bd3 Rh5 246.Re6 Rg5 247.Rh6 Rc5 248.Bc4 Rg5 249.Ra6 Ra5 250.Rh6 Rg5 251.Rh4 Ka5 252.Rh2 Rg3 253.Kd4 Rg5 254.Bd5 Ka4 255.Kc5 Rg3 256.Ra2 Ra3 257.Rb2 Rg3 258.Rh2 Rc3 259.Bc4 Rg3 260.Rb2 Rg5 261.Bd5 Rg3 262.Rh2 Rc3 263.Bc4 Rg3 264.Rh8 Ka3 265.Ra8 Kb2 266.Ra2 Kb1 267.Rf2 Kc1 268.Kd4 Kd1 269.Bd3 Rg7 1/2-1/2