Level
5-Queen
Chess Diagram
[Event "Puzzle #78"][Date "2009.07.17"][Result "1-0"][SetUp "1"][FEN "8/8/8/2p5/2Pp4/3K2Pk/7P/8 w - - 0 1"]
We had a very good final lesson of the school year, particing King and pawns endgames. It is my hope you guys will be able to play well such endgames at any time in future. Let's look at one more position to make sure you can apply all the principles if it is needed. The above position is very instructive and it was published by Lisitzin in his chess manual. It is interesting to note the winning method works even if Kd3 and c4, plus c5 and d4 would be placed one file to the left. Your tasks are:
a) White to move and win
b) Explain your solution
Total available points for this puzzle is 20. The answers will be published next week together with puzzle #79.
Puzzle #77 solution:
I am happy to see the majority of you guys understood the Lucena position. Two answers were special this time, so here they are as prepared by Karl and Rick (see solution):
[Event "Puzzle #77"][Date "2009.07.10"][Result "1-0"][SetUp "1"][FEN "4k1K1/6P1/8/8/8/8/7r/5R2 b - - 0 1"]1...Rh3 {The black Rook wants to remain on the h-file. Black really doesn't want the white pawn to promote, so he doesn't want to let the King get out of the g8 square, the pawn's queening square. The black King blocks the white King from escaping to f8 and f7, and the black Rook protects the squares h7 and h8. Black will want to stay in that position} (1...Re2 {This is an alternative solution if black decides to protect his king} 2.Rf4 {If the black Rook still protects his king, then the white King can come out the other way (Kh7) and do the Lucena position} ({Rick found an alternate possibility} 2.Rh1 Re3 {Black must guard the e-file to prevent white from checking the black King and then building a bridge, so there's nothing better than playing a waiting move} 3.Kh7 Re7 {The only way to stop the pawn} 4.Kh8 {There is no way to avoid promotion with the white King safely protected by perpetual checks in the corner. Black is lost}) ({Eugen} 2.Kh7 {This works as well and quicker since the black king is on e8} 2...Rh2+ 3.Kg6 Rg2+ 4.Kf6 Rg3 5.Rf5 Rg2 6.Re5+ Kd7 7.Rg5 {White wins})) 2.Re1+ Kd7 3.Re4 {White wants to do the Lucena position now. If the white King simply goes out without the Rook going to e4, then the black Rook will keep checking the white King, and we will soon be back to the position that we started with. White wants to form a bridge, and cannot do so unless he has a Rook to protect the King. If white pushes his Rook too far, then the black King will be able to attack. If white doesn't push his Rook a sufficient number of spaces, then the white king will not be able to reach it} 3...Rh1 4.Kf7 Rf1+ 5.Kg6 Rg1+ 6.Kf6 {The white King needs to protect the pawn, and do what ever it takes to promote it} 6...Rf1+ 7.Kg5 Rg1+ 8.Rg4 {How was white able to achieve this? By keeping the black King two squares away from the white pawn}
Correct solutions:
Karl - 20 points
Andy Q, Joshua, Rick - 19 points
Wilson, Nathaniel - 18 points
Alex Ge, Marcus - 5 points
Standings:
Joshua - 51 points
Andy Q - 49 points
Karl - 37 points
Wilson - 32 points
Alex Ge - 25 points
James - 23 points
Katerina, Andy Y - 20 points
Rick, Marcus - 19 points
Nathaniel - 18 points
a) White to move and win
b) Explain your solution
Total available points for this puzzle is 20. The answers will be published next week together with puzzle #79.
Puzzle #77 solution:
I am happy to see the majority of you guys understood the Lucena position. Two answers were special this time, so here they are as prepared by Karl and Rick (see solution):
[Event "Puzzle #77"][Date "2009.07.10"][Result "1-0"][SetUp "1"][FEN "4k1K1/6P1/8/8/8/8/7r/5R2 b - - 0 1"]1...Rh3 {The black Rook wants to remain on the h-file. Black really doesn't want the white pawn to promote, so he doesn't want to let the King get out of the g8 square, the pawn's queening square. The black King blocks the white King from escaping to f8 and f7, and the black Rook protects the squares h7 and h8. Black will want to stay in that position} (1...Re2 {This is an alternative solution if black decides to protect his king} 2.Rf4 {If the black Rook still protects his king, then the white King can come out the other way (Kh7) and do the Lucena position} ({Rick found an alternate possibility} 2.Rh1 Re3 {Black must guard the e-file to prevent white from checking the black King and then building a bridge, so there's nothing better than playing a waiting move} 3.Kh7 Re7 {The only way to stop the pawn} 4.Kh8 {There is no way to avoid promotion with the white King safely protected by perpetual checks in the corner. Black is lost}) ({Eugen} 2.Kh7 {This works as well and quicker since the black king is on e8} 2...Rh2+ 3.Kg6 Rg2+ 4.Kf6 Rg3 5.Rf5 Rg2 6.Re5+ Kd7 7.Rg5 {White wins})) 2.Re1+ Kd7 3.Re4 {White wants to do the Lucena position now. If the white King simply goes out without the Rook going to e4, then the black Rook will keep checking the white King, and we will soon be back to the position that we started with. White wants to form a bridge, and cannot do so unless he has a Rook to protect the King. If white pushes his Rook too far, then the black King will be able to attack. If white doesn't push his Rook a sufficient number of spaces, then the white king will not be able to reach it} 3...Rh1 4.Kf7 Rf1+ 5.Kg6 Rg1+ 6.Kf6 {The white King needs to protect the pawn, and do what ever it takes to promote it} 6...Rf1+ 7.Kg5 Rg1+ 8.Rg4 {How was white able to achieve this? By keeping the black King two squares away from the white pawn}
Correct solutions:
Karl - 20 points
Andy Q, Joshua, Rick - 19 points
Wilson, Nathaniel - 18 points
Alex Ge, Marcus - 5 points
Standings:
Joshua - 51 points
Andy Q - 49 points
Karl - 37 points
Wilson - 32 points
Alex Ge - 25 points
James - 23 points
Katerina, Andy Y - 20 points
Rick, Marcus - 19 points
Nathaniel - 18 points
Rule of the square