18 Jan 13
So, I recently got into my first R+B vs R endgame. I tried to do it in the 50 moves available, then offered a draw when it was clear that I couldn't mate in time. My challenge is, I know it is a technical win, but can YOU finish this off in the moves available against the best response without a box? I dropped some moves by repetition, but even still I don't think I could have finished it off in time. Answers on a postcard please 🙂
The countdown starts at move 57...
Game 9603028
18 Jan 13
1 edit
Originally posted by morgskiWhat I learned from my old book "Chess Self-teacher" by Al Horowitz is the general rule of thumb with endings without pawns is to cancel out like pieces and determine if what remains can result in a forced mate. In this case, we see that the pawn can be captured with check and we have the R+B vs R endgame. Since the Rooks can be canceled out and a lone bishop can't force a checkmate, the game should be a draw with best play on both sides.
So, I recently got into my first R+B vs R endgame. I tried to do it in the 50 moves available, then offered a draw when it was clear that I couldn't mate in time. My challenge is, I know it is a technical win, but can YOU finish this off in the moves available against the best response without a box? I dropped some moves by repetition, but even still I don Ke5e4 Rh5h4 76. Ke4d3 Kb4b5 77. Bf5e4 Kb5b6 78. Kd3d4 1/2-1/2[/pgn]
Wikipedia says the side with the bishop can force a win in certain position even though it is very difficult.
http://en.wikipedia.org/wiki/Rook_and_bishop_versus_rook_endgame
18 Jan 13
Originally posted by morgskiI doubt if I could do it within 50 moves even if I could force it into one of the winning positions, because I have not studied this type of ending. If it happened OTB I would probably just agree to a draw.
I knew that, thank you. The idea was to have a go and see if you can do it unaided...
18 Jan 13
Originally posted by RJHinds"You do not learn if you do not try" Morgski, 2013
I doubt if I could do it within 50 moves even if I could force it into one of the winning positions, because I have not studied this type of ending. If it happened OTB I would probably just agree to a draw.
Trial and error is the best way to realise what you don't know. Studying comes later.
Anyway, we digress. It is possible to win with this combo of pieces and unlimited moves, I could see a way to do it. Just not under 50. I want to know if that is because I messed up with my early moves, or whether this ending can only be done within the move limit in certain positions (e.g. defending king doesn't control the centre).
18 Jan 13
Originally posted by morgskiOkay, I tried it and I went over 50 moves without mating. However, I was able to get the other king to the edge of the board, but I could not figure how to get my king up close in opposition like in the diagrams shown in Wikipedia.
"You do not learn if you do not try" Morgski, 2013
Trial and error is the best way to realise what you don't know. Studying comes later.
Anyway, we digress. It is possible to win with this combo of pieces and unlimited moves, I could see a way to do it. Just not under 50. I want to know if that is because I messed up with my early moves, or whether this ...[text shortened]... within the move limit in certain positions (e.g. defending king doesn't control the centre).
18 Jan 13
Tough one Morgski. I may be wrong, but if I remember correctly there are some instances where a forced win is possible, but it takes more than 50 moves. I think it was around 75 moves. FIDE changed their rule to 100 moves, then changed back to 50. 😕
Maybe someone else can correct me if I am wrong.
(RJ if you think I am wrong, send me a game and we'll slap the snot outta each other over the board) 😛😛
19 Jan 13
1 edit
Originally posted by morgskiWhat does that mean?
"You do not learn if you do not try" Morgski, 2013
Trial and error is the best way to realise what you don't know. Studying comes later.
You thought that you knew and when you didn't do it you realised that you didn't knew?
I think it works the other way around: you study it because you know that you don't know it and when it comes in a game you do it(when and if it is winning).
19 Jan 13
Originally posted by ChessPraxisNo you are not wrong.
Tough one Morgski. I may be wrong, but if I remember correctly there are some instances where a forced win is possible, but it takes more than 50 moves. I think it was around 75 moves. FIDE changed their rule to 100 moves, then changed back to 50. 😕
Maybe someone else can correct me if I am wrong.
(RJ if you think I am wrong, send me a game and we'll slap the snot outta each other over the board) 😛😛
FIDE indeed changed the 50 move rule to 75 (according to Karsten Muller) but that decision was reversed.
For the attacking side to win it is necessary to force the enemy king to the edge of the board so the 2 main defensive methods for the defensive side(Cochrane defense and Second rank defense) attempt of course to prevent exactly that.
Philidor has shown when and how the attacking side can win.
[Result "1-0"]
[SetUp "1"]
[FEN "3k4/4r3/3K4/3B4/8/8/8/5R2 w - - 0 1"]
1. Rf8+ Re8 2. Rf7 Re2 3. Rh7 Re1 4. Rb7 Rc1 5. Bb3 Rc3 6. Be6 Rd3+ 7. Bd5 Rc3
8. Rd7+ Kc8 9. Rh7 Kb8 10. Rb7+ Kc8 11. Rb4 Kd8 12. Bc4 Kc8 13. Be6+ Kd8 14.
Rb8+ Rc8 15. Rxc8# 1-0
The mating net that white sets appears in many middlegame positions too so it's a good pattern to be studied and recognised.
19 Jan 13
Originally posted by Roper300
No you are not wrong.
FIDE indeed changed the 50 move rule to 75 (according to Karsten Muller) but that decision was reversed.
For the attacking side to win it is necessary to force the enemy king to the edge of the board so the 2 main defensive methods for the defensive side(Cochrane defense and Second rank defense) attempt of course to prevent exactly t ...[text shortened]... ars in many middlegame positions too so it's a good pattern to be studied and recognised.
19 Jan 13
5 edits
I will show only one variation to force the enemy king to the edge of the board with kings in opposition, because black can vary his move at several points and may be a little more stubborn, but I believe the king can still be driven to the edge of the board. It was easier to drive the king to the side of the board instead of to the top.
Now if anyone can show how this can be forced into a winning position, then we will know if the original position is a draw or a forced win.
Here are the two main wining position shown in wikipedia
Philidor position
Lolli position
19 Jan 13
Originally posted by Roper300I meant that, for me at least, I don't fully understand the problem at hand unless I have had a go myself. Same goes for openings, when I was learning I could read all I liked about the Dragon, Scandinavian etc., but it was only by trying them that I learnt their strengths, weaknesses, and the holes in my understanding.
What does that mean?
You thought that you knew and when you didn't do it you realised that you didn't knew?
I think it works the other way around: you study it because you know that you don't know it and when it comes in a game you do it(when and if it is winning).
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19 Jan 13
Originally posted by morgskiAssuming no side makes an error, the position is drawn regardless of number of moves.
So, I recently got into my first R+B vs R endgame. I tried to do it in the 50 moves available, then offered a draw when it was clear that I couldn't mate in time. My challenge is, I know it is a technical win, but can YOU finish this off in the moves available against the best response without a box? I dropped some moves by repetition, but even still I don ...[text shortened]... Ke5e4 Rh5h4 76. Ke4d3 Kb4b5 77. Bf5e4 Kb5b6 78. Kd3d4 1/2-1/2[/pgn]
Post game analysis I use this tool (although it only allows 6 pieces including kings). Take a look at this tablebase. It's an excellent tool.
http://www.k4it.de/index.php?topic=egtb&lang=en