Puzzle of the week #29

Submitted by oldadmin on

Zugzwang

Level
3-Bishop
Chess Diagram
[Event "Puzzle #29"][Date "2008.07.16"][Result "1-0"][SetUp "1"][FEN "8/6p1/3p1k2/p1p1p3/4PrRP/P2PKP2/2P5/8 b - - 0 34"]
These days the best juniors in the country compete for the national titles in 12 age group categories. Here on the website we are keeping track of the performance of our present or past club members, plus Maggie. There are lots of interesting games to follow, with big upsets and disappointing defeats like in any other tournament. However we can say for sure that junior chess in Canada is becoming stronger from the younger age up (as it should be). Today's puzzle features a big upset in the game: Dylan Parker, BC (1512) - Jerry Wang, ON (1874), boys U14. After 34 moves (last one was 34.Rg4 ...) Dylan's opponent resigned in the following position (see diagram). Questions:
a) Was Black's decision correct? Please explain (5 points)
b) Come up with a possible line (no longer than 10 moves) at best play for both sides (5 points)

Total available points for this puzzle is 10. The answers will be published next week together with puzzle #30.

Puzzle #28 solution:
This time I got 4 different answers from 4 different players; very interesting! Only one of them guessed the result of the game, but that was not the correct answer to question "a". Here are the correct answers:
a) the most likely result in this position should be a win for Black. There are way too many pawns helping the Bishop, the h4-pawn is a target and should have been captured by Black immediately creating a passed pawn, plus the group "e7-f7-f5" would transform into a 2 passed, connected pawns vs nobody
b) a possible winning line could look like this (see below):
[Event "Puzzle #28"][Date "2008.07.10"][Result "1/2-1/2"][SetUp "1"][FEN "2R5/4pp1k/2p2b2/2p2p1p/7P/5P2/4K3/8 b - - 0 46"]{In the game} 46...c4?! ({A possible winning line} 46...Bxh4 47.Rxc6 Bg3 48.Rxc5 e5 {Black needs to be aggressive with his pawns} 49.Kf1 Kg6 50.Rc6+ Kg5 51.Kg2 Bh4 52.Rc7 f6 53.Rg7+ Kf4 54.Rh7 e4 55.fxe4 fxe4 56.Rxh5 Kg4 {Probably white can hold on}) 47.Rxc6 c3? 48.Rxf6!! {Splendid sacrifice!! It is interesting to note that even today's software does not detect this move in the top 5 choices, considering that White is in a worst position anyway. However once you enter it, the chess engine is capable to see the draw} 48...exf6 49.f4 Kg8 50.Kd3 Kf8 51.Kxc3 Ke7 52.Kc4 Kd6 53.Kd4 {Draw}

Correct solutions:
Joshua - 8.0 points
John and Wilson - 7.0 points
Jeremy - 2.0 points

Standings:
25.0 John
21.0 Wilson
18.0 Joshua
13.0 Jeremy
10.0 Jacob and Karl