m (→‎Stefan (1005) vs Amir (1000))
m (→‎Stefan (1005) vs Amir (1000))
Line 495: Line 495:
  
 
1. e4 c6 { Caro-Kann Defense, General } 2. d4 f6?! { (0.44 → 1.33) Inaccuracy. The best move was d5. } (2... d5 3. e5 Bf5 4. Nf3 e6 5. Be2 Nd7 6. O-O) 3. Nc3 Nh6? { (1.25 → 4.12) Mistake. The best move was d6. } (3... d6 4. Nf3 e5 5. Bc4 b5 6. Bb3 Qc7 7. O-O Ne7 8. dxe5 dxe5 9. Be3 Nd7 10. a4) 4. Nh3?? { (4.12 → 0.80) Blunder. The best move was Bxh6. } (4. Bxh6 d5 5. Bf4 dxe4 6. Nxe4 Bf5 7. Qe2 e6 8. O-O-O Na6 9. g4 Bg6 10. Nf3 Nb4 11. Nc5 Qd5 12. Nxe6 Nxa2+ 13. Kb1) 4... e6? { (0.80 → 2.49) Mistake. The best move was Nf7. } (4... Nf7 5. Be2 e6 6. O-O d5 7. Nf4 e5 8. Nh5 g6 9. dxe5 gxh5 10. exd5 fxe5) 5. Bd3? { (2.49 → 0.85) Mistake. The best move was Bxh6. } (5. Bxh6 gxh6 6. Qh5+ Ke7 7. O-O-O Bg7 8. e5 d5 9. exd6+ Qxd6 10. Kb1 Kf8 11. g3 Qe7 12. Nf4 Qe8 13. Qh4 Qe7 14. Bh3 f5) 5... Bd6?? { (0.85 → 4.24) Blunder. The best move was Nf7. } (5... Nf7 6. O-O Na6 7. Be3 Be7 8. f4 O-O 9. Nf2 b5 10. e5 f5 11. a4 bxa4 12. Be2 Nb4 13. Rxa4 Bb7) 6. Bxh6 gxh6 7. Qh5+ Ke7?! { (3.75 → 4.45) Inaccuracy. The best move was Kf8. } (7... Kf8 8. e5 Be7 9. O-O-O d5 10. exd6 Bxd6 11. Ne4 Kg7 12. Be2 Qe7 13. Rd3 Rf8 14. Nxd6 Qxd6 15. Rg3+ Kh8 16. Qxh6 Rf7) 8. Qxh6? { (4.45 → 1.90) Mistake. The best move was e5. } (8. e5 fxe5 9. dxe5 Bc7 10. Ne4 Qf8 11. Qh4+ Ke8 12. Nf6+ Kf7 13. f4 Bd8 14. Qh5+ Ke7 15. O-O-O Ba5 16. Qh4 Kd8 17. Nd5+ Ke8) 8... Qg8? { (1.90 → 4.48) Mistake. The best move was Qf8. } (8... Qf8 9. Qe3 Kd8 10. O-O-O a5 11. e5 Be7 12. exf6 Bxf6 13. Ne4 Be7 14. Kb1 Na6 15. Nf4 b5 16. c3 Nc7) 9. g3? { (4.48 → 2.07) Mistake. The best move was e5. } (9. e5 Bb4 10. exf6+ Kd8 11. Ng5 Qf8 12. Qxf8+ Rxf8 13. Nxh7 Rh8 14. a3 Bxc3+ 15. bxc3 d5 16. Kd2 Nd7 17. Rae1) 9... f5? { (2.07 → 5.06) Mistake. The best move was e5. } (9... e5 10. O-O Qf8 11. Qd2 exd4 12. Ne2 c5 13. Nhf4 b6 14. Nd5+ Ke8 15. Nef4 Bb7 16. c3 Nc6 17. Be2 Rc8 18. Bh5+ Kd8) 10. e5? { (5.06 → 3.60) Mistake. The best move was Qh4+. } (10. Qh4+ Kf7 11. exf5 Be7 12. Qf4 d5 13. O-O Qf8 14. fxe6+ Kg8 15. Qe3 Na6 16. a3 h5 17. Nf4) 10... Bb4 11. O-O? { (3.34 → 2.33) Mistake. The best move was g4. } (11. g4 Kd8 12. gxf5 Qf8 13. Qxf8+ Rxf8 14. f6 d6 15. O-O-O dxe5 16. dxe5 Nd7 17. Bxh7 Bxc3) 11... c5?? { (2.33 → 8.24) Blunder. The best move was Kd8. } (11... Kd8 12. Ne2 Be7 13. c4 b6 14. a3 Kc7 15. Qe3 h5 16. Nhf4 h4) 12. Nb5 Nc6? { (8.21 → Mate in 2) Checkmate is now unavoidable. The best move was Ke8. } (12... Ke8 13. Qh4 d5 14. exd6 Qg7 15. Nc7+ Kd7 16. dxc5 Bxc5 17. Bb5+ Nc6 18. Nxa8 a6 19. Bxc6+ Kxc6 20. b4 Qd4 21. bxc5 Qxh4 22. gxh4) 13. Qf6+ Ke8 14. Nc7# { Black is checkmated } 1-0
 
1. e4 c6 { Caro-Kann Defense, General } 2. d4 f6?! { (0.44 → 1.33) Inaccuracy. The best move was d5. } (2... d5 3. e5 Bf5 4. Nf3 e6 5. Be2 Nd7 6. O-O) 3. Nc3 Nh6? { (1.25 → 4.12) Mistake. The best move was d6. } (3... d6 4. Nf3 e5 5. Bc4 b5 6. Bb3 Qc7 7. O-O Ne7 8. dxe5 dxe5 9. Be3 Nd7 10. a4) 4. Nh3?? { (4.12 → 0.80) Blunder. The best move was Bxh6. } (4. Bxh6 d5 5. Bf4 dxe4 6. Nxe4 Bf5 7. Qe2 e6 8. O-O-O Na6 9. g4 Bg6 10. Nf3 Nb4 11. Nc5 Qd5 12. Nxe6 Nxa2+ 13. Kb1) 4... e6? { (0.80 → 2.49) Mistake. The best move was Nf7. } (4... Nf7 5. Be2 e6 6. O-O d5 7. Nf4 e5 8. Nh5 g6 9. dxe5 gxh5 10. exd5 fxe5) 5. Bd3? { (2.49 → 0.85) Mistake. The best move was Bxh6. } (5. Bxh6 gxh6 6. Qh5+ Ke7 7. O-O-O Bg7 8. e5 d5 9. exd6+ Qxd6 10. Kb1 Kf8 11. g3 Qe7 12. Nf4 Qe8 13. Qh4 Qe7 14. Bh3 f5) 5... Bd6?? { (0.85 → 4.24) Blunder. The best move was Nf7. } (5... Nf7 6. O-O Na6 7. Be3 Be7 8. f4 O-O 9. Nf2 b5 10. e5 f5 11. a4 bxa4 12. Be2 Nb4 13. Rxa4 Bb7) 6. Bxh6 gxh6 7. Qh5+ Ke7?! { (3.75 → 4.45) Inaccuracy. The best move was Kf8. } (7... Kf8 8. e5 Be7 9. O-O-O d5 10. exd6 Bxd6 11. Ne4 Kg7 12. Be2 Qe7 13. Rd3 Rf8 14. Nxd6 Qxd6 15. Rg3+ Kh8 16. Qxh6 Rf7) 8. Qxh6? { (4.45 → 1.90) Mistake. The best move was e5. } (8. e5 fxe5 9. dxe5 Bc7 10. Ne4 Qf8 11. Qh4+ Ke8 12. Nf6+ Kf7 13. f4 Bd8 14. Qh5+ Ke7 15. O-O-O Ba5 16. Qh4 Kd8 17. Nd5+ Ke8) 8... Qg8? { (1.90 → 4.48) Mistake. The best move was Qf8. } (8... Qf8 9. Qe3 Kd8 10. O-O-O a5 11. e5 Be7 12. exf6 Bxf6 13. Ne4 Be7 14. Kb1 Na6 15. Nf4 b5 16. c3 Nc7) 9. g3? { (4.48 → 2.07) Mistake. The best move was e5. } (9. e5 Bb4 10. exf6+ Kd8 11. Ng5 Qf8 12. Qxf8+ Rxf8 13. Nxh7 Rh8 14. a3 Bxc3+ 15. bxc3 d5 16. Kd2 Nd7 17. Rae1) 9... f5? { (2.07 → 5.06) Mistake. The best move was e5. } (9... e5 10. O-O Qf8 11. Qd2 exd4 12. Ne2 c5 13. Nhf4 b6 14. Nd5+ Ke8 15. Nef4 Bb7 16. c3 Nc6 17. Be2 Rc8 18. Bh5+ Kd8) 10. e5? { (5.06 → 3.60) Mistake. The best move was Qh4+. } (10. Qh4+ Kf7 11. exf5 Be7 12. Qf4 d5 13. O-O Qf8 14. fxe6+ Kg8 15. Qe3 Na6 16. a3 h5 17. Nf4) 10... Bb4 11. O-O? { (3.34 → 2.33) Mistake. The best move was g4. } (11. g4 Kd8 12. gxf5 Qf8 13. Qxf8+ Rxf8 14. f6 d6 15. O-O-O dxe5 16. dxe5 Nd7 17. Bxh7 Bxc3) 11... c5?? { (2.33 → 8.24) Blunder. The best move was Kd8. } (11... Kd8 12. Ne2 Be7 13. c4 b6 14. a3 Kc7 15. Qe3 h5 16. Nhf4 h4) 12. Nb5 Nc6? { (8.21 → Mate in 2) Checkmate is now unavoidable. The best move was Ke8. } (12... Ke8 13. Qh4 d5 14. exd6 Qg7 15. Nc7+ Kd7 16. dxc5 Bxc5 17. Bb5+ Nc6 18. Nxa8 a6 19. Bxc6+ Kxc6 20. b4 Qd4 21. bxc5 Qxh4 22. gxh4) 13. Qf6+ Ke8 14. Nc7# { Black is checkmated } 1-0
 +
</pgn>
 +
 +
== Amir (953) vs Juan Pablo (927) ==
 +
 +
A late PolaChess session today, since Amir was looking for his new place to live (which he found, by the way). Everybody was expecting a bold queen sacrifice from Juan Pablo, which, not disappointingly, duly came on precisely the traditional 12th move. We let you discover this fantastic queen blunder of majestic proportion which, as it should to have all its savor, was played on a strong, if not winning, position.
 +
 +
<center><wz tip="Don't touch the queen! Don't touch the queen!">[[File:polachess-17March2015.jpeg|400px]]</wz></center>
 +
 +
<pgn>
 +
[Event "Casual game"]
 +
[Site "http://lichess.org/YeZ9kpDn"]
 +
[Date "2015.03.17"]
 +
[White "Amir"]
 +
[Black "Pablo"]
 +
[Result "1-0"]
 +
[WhiteElo "?"]
 +
[BlackElo "?"]
 +
[PlyCount "25"]
 +
[Variant "Standard"]
 +
[TimeControl "-"]
 +
[ECO "C20"]
 +
[Opening "King Pawn Game, General"]
 +
[Annotator "lichess.org"]
 +
 +
1. e4 e5 { King Pawn Game, General } 2. g3 Nf6 3. Bd3?! { (-0.18 → -1.05) Inaccuracy. The best move was Nc3. } (3. Nc3 Bc5 4. f4 d6 5. fxe5 dxe5 6. Nf3 Bg4) 3... d5 4. exd5 Nxd5 5. Bb5+?! { (-0.57 → -1.16) Inaccuracy. The best move was Nc3. } (5. Nc3 Be7 6. Be4 c6 7. d4 exd4 8. Nxd5 cxd5 9. Bg2 Nc6 10. Ne2 O-O 11. O-O Bg4 12. h3 Be6 13. Nxd4 Qb6 14. Nxe6 fxe6) 5... c6 6. Bd3 Bc5 7. Qh5?! { (-1.06 → -1.58) Inaccuracy. The best move was Nc3. } (7. Nc3 Nb4 8. Be4 Qd4 9. Qe2 f5 10. a3 fxe4 11. axb4 Bxb4 12. f3 O-O) 7... Nf6?! { (-1.58 → -0.71) Inaccuracy. The best move was Be6. } (7... Be6 8. Nc3 Nd7 9. Nf3 g6 10. Qg5 Nb4 11. Qxd8+ Rxd8 12. Be4 Bd5 13. Kd1 Bxf2) 8. Qxe5+ Be7 9. Qg5?! { (-0.60 → -1.48) Inaccuracy. The best move was Nc3. } (9. Nc3 Nbd7 10. Qf4 Nc5 11. Bc4 Ne6 12. Bxe6 Bxe6 13. Nge2 Bh3 14. Rg1 O-O 15. d3 Re8 16. Be3 Bd6 17. Qd4 Bg4 18. O-O-O) 9... O-O 10. Nf3? { (-1.51 → -2.82) Mistake. The best move was Ne2. } (10. Ne2 Nbd7 11. Nbc3 Nd5 12. Qg4 Nb4 13. Qe4 Nf6 14. Qg2 Nxd3+ 15. cxd3 Re8 16. O-O Bf5 17. d4 Bb4 18. f3 Bd3 19. Rf2 Qe7) 10... Na6? { (-2.82 → -1.56) Mistake. The best move was Ng4. } (10... Ng4 11. Qf4 Bd6 12. Qg5 Re8+ 13. Be2 f6 14. Qh5 g6 15. Qh4 Rxe2+ 16. Kxe2 Qb6 17. d4) 11. Ne5? { (-1.56 → -3.18) Mistake. The best move was O-O. } (11. O-O Nb4 12. Nc3 Nxd3 13. cxd3 Nd5 14. Qe5 Nb4 15. Qe4 Nc2 16. Rb1 Bf6 17. Na4 Bh3 18. Rd1 Re8 19. Qc4 Nd4 20. Nxd4 Qxd4) 11... Nd5? { (-3.18 → -1.60) Mistake. The best move was Qd5. } (11... Qd5 12. f3 Bd6 13. Bc4 Qxe5+ 14. Qxe5 Bxe5 15. c3 Bd6 16. d4 Bf5 17. O-O Rfe8 18. Bg5 Nd5 19. Nd2 b5 20. Bxd5 cxd5 21. Rfe1) 12. Qh5 Qe8?? { (-1.63 → Mate in 1) Checkmate is now unavoidable. The best move was Nf6. } (12... Nf6 13. Qe2 Nb4 14. Nc3 Re8 15. Bc4 Nxc2+ 16. Kd1 Nxa1 17. Nxf7 Qd4) 13. Qxh7# { Black is checkmated } 1-0
 
</pgn>
 
</pgn>
  

Revision as of 19:01, 17 March 2015

Contents

PolaChess

The PolaChess tournament is the ongoing PolaFlow chess tournament. It is a Round-robin, 15 minutes time, 0 increment tournament played during coffee time. Both a PolÆlO rating and centipawns are computed. The person in charge is Juan Pablo.

Polachess-first-game.jpeg

PolÆlO

An Elo is computed, with a $K=32$ constant and with 5 provisional ratings for players not part of the PolaChess pool (we assumed established ratings for everybody who joined the tournament at $t=0$, which is not a problem as their ratings will converge but we need to take into account occasional games as provided by visitors). Specifically, the $K$ factor is scaled by $3/\big(4(5-i)\big)$ (i.e., down) for the established player and by $3-(i-1)/2$ (i.e., up) for his opponent for the first $i<5$ games of the new player, after which point $K=32$ again. Explicitly, the $K$ constants for the new player go:

96, 80, 64, 48, and 32 thereafter

while it goes, for the established player:

6, 8, 12, 24, and 32 thereafter

Games

Carlos (1000) vs Camilo (1000)

13 February (2015)

Fabrice (1000) vs David (1000)

16 February (2015)

Carlos (1016) vs Stefan (1000)

17 February (2015) (photo)

Pablo (1000) vs Fabrice (1016)

18 February (2015)

Santiago (1000) vs Carlos (1031)

Camilo (984) vs Stefan (985)

David (984) vs Carlos (1046)

23 February (2015) — Blunderful.

Stefan (1001) vs Pablo (985)

Santiago (985) vs David (1003)

Pablo (970) vs David (1018)

David (1032) vs Fabrice (1031)

Fabrice (1047) vs Stefan (1016)

The end was not recorded as it was too fast for the transcript (Pablo). Apparently an illegal move was made with a rook. The game ended in checkmate in a race to flag for time.

David (1016) vs Stefan (1001)

Fabrice (1062) vs Carlos (1027)

Pablo (956) vs Camilo (968)

Camilo wins on time. Interestingly, 24. Qd6+?! is not a blunder (only a mistake). The next move, however, is a proper queen panick moment.

Stefan (1018) vs Fabrice (1076)

The end was not recorded as it was too fast for the transcript (Pablo). The game ended in checkmate shortly after the last position shown.

Santiago (970) vs Camilo (983)

Shortest game so far, which left us time to play a king of the hill variation (which Camilo won, against Fabrice, by checkmate on a too daring king).

Santiago (987) vs Pablo (941)

In a raging fury against our Colombian community, Santiago proceeds to calmly walk his way back up the ladder of the tournament, methodically resisting the attacks of White who, in their traditional style, succumb to their own pressure and split out to surrender their queen on an otherwise leading position. The shat queen moment—this move of the game where Juan Pablo becomes chess-blind and positions his dame in front of a pawn, bishop or right below the roofs of a knight—occurred here on the (Friday the) 13th move. It was then just a matter of carefully moving the heavy Black artillery left around, with little but enough time left to enforce checkmate. Playing with psychology on his side, Santiago allowed himself the occasional glance through the window, à la Bobby, which was a nice touch.

Camilo (966) vs David (999)

A game of tension, of tension going too far. First 10 moves or so have been slowly, carefully considered by both sides and getting the pot to almost boiling point. Then David blunders his queen away, 11. Bd3?? Even then, to strike mercilessly, Camilo took his time, and brought the heavy knight falling with all the weight of an actual horse on the square that meant defeat for our French contender. But there's nothing that you can do to vex David's attitude. He regarded this move as mere trifle, displaced his king and carried on with a face of steel. Time was still equal. But with time passing and nothing to loose, it was easy for Black to arrogantly pretend they could still play, and with the face of conquest, advance a minuscule little pawn towards recovering the wasted queen. White started to play faster (which is good) and with too much confidence (which is not), with some irrational fixation on delivering check. See 22. Qc4+?, letting the knight go away. At this point, or not too far, a girl who popped out of nowhere tried to get under the table to reach something below Camilo's bench. Upon inquiry, and thankfully, it turned out to be only for a coin that rolled all the way from the vending machine to our competitor. We had to pay the girl to go away. Too late. On 26th move, the blunder of the day changed the game's fate. In a mate-in-5 position, when everybody started to relax and think about the coin below the bench, Camilo spin out of control: first sacrifice of a bishop, 26. Bxa6+? then throwing the queen in its wake, 27 Qxa6+?? The move was stopped in mid-air, in a frozen time and space with only a resounding "too late, too late" from David, detonating in a cafetaria getting a moment's interest into an apparent scandal. Then in time trouble, psychologically ruined, pursuing illusory checkmates through pointless checks, only defeat could follow for White, who lost on time.

Fabrice (1089) vs Javier (1000)

We have a new player, Javier, also the strongest one (playing in a club), so this is great news for our competition. Javier enters with the provisional rating rules, so his rating changes a lot, sinking to 964 as he lost the game, while Fabrice's (yours truly, writing this comment) changes little, winning only 2 points in what was the most difficult game so far. Actually the game was a win for Black, who had a mate position in move 31. Qg4# Chess being a game where a single mistake can overturn everything, since 31. g6+?? was played instead, a Berezina was turned into a Campo Formio. A mate had been announced, and as I had seen the mate with queen, I accepted the claim as valid, but the Referee (Pablo) observed this was not checkmate, so the game carried on, and after forcing the exchange of queens, Black was in the mental despair situation and did not try to fight against the rook. A careless knight move led to his capture on discovering a check, and Black resigned. This is a victory from a lost game. But aren't many victories like that? (especially when involving French players?) Like this, everybody's a winner: the good chess player, who loses on a blunder and the loser, who wins as a patzer. To make things worst, on move 15. a super-castling 15. O-O-O-O was attempted, conveniently getting the king on d1, but of course the referee objected, and everybody laughed his ass off, not letting me add another quantum move up my sleeve of illegal tricks. Still, the game continued.

The main feature of the game as far as I am concerned is my move 7. c3?? which the audience took for what it was: a blunder, but assuming a stupid oversight, while it was really a gambit. Which one? This is the variation I had in mind (you can play it in the game below as the 2nd variation):

7. Nh2 h6xg5 (opening the column)
8. h4xg5 (menacing to take back the sacrificed piece)

The knight has ultimately to move, leaving the Black king naked to an attack from the White queen supported by the king's bishop, and pinned by the White king's bishop. This leads to aggressive attack that, in time battle, may be worth the small loss in material. I'm fairly sure in the queenside castle of Black, this provides an actual advantage (my experience is that strong players tend to reject this gambit). Here, though, the knight was in the way, Javier is a good player, so he had time to develop his pieces to turn this hurried and lame attack into a sound counter-attack. In fact, even if I hadn't shat the horse in the middle, this was a mistake, since, so the computer analyzes:

8. ... d5 (exchanging knight for bishop)
9. Bb3 (holding the pin) Nh7 (keeping the knight)
10. g6

The queen still looks dangerous but the analysis shows that it's still better for Black.

Stefan (1005) vs Amir (1000)

Another new player, Amir Rahmani, joined the tournament to defend the colors of Isfahan against Stefan who took a bye from our club player till Wednesday. A strange opening and a dangerous unconvering of the king-side let Stefan, who was mentally and physically preparing himself to destroy Javier, have an easy win. Tomorrow, Amir vs Juan Pablo. Bets are opened. Will the "shat queen" get in the way of another assured victory? Or will Amir toy again with irregular openings?

Amir (953) vs Juan Pablo (927)

A late PolaChess session today, since Amir was looking for his new place to live (which he found, by the way). Everybody was expecting a bold queen sacrifice from Juan Pablo, which, not disappointingly, duly came on precisely the traditional 12th move. We let you discover this fantastic queen blunder of majestic proportion which, as it should to have all its savor, was played on a strong, if not winning, position.

Polachess-17March2015.jpeg

Games to come

Based on Computer's random sampling. Games that cannot take place are either skipped of flushed to the end.

Decided at the last minute on people's availability.

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