A possible case of cheating

[mar]

If you think the tactics are that easy for a 1700 then play the game with a weak engine (e.g. Anmon rated 2534 on CCRL) and see if it can find the moves black played.

Anmon can see the moves easily. In fact it sees all moves (after Qxb4) except for Kd2 of course. I certainly don't consider Anmon weak

[mar]

Hi Martin,

just because there's nothing special in 25....Kg8 it is a very suspicious move.

According to Houdini 2.0c here Black has at least 15 (!) moves scoring from -0.13 to +0.23 (depth 24), and black found just the best move, an apparently innocent move like Kg8, the move preferred by Houdini. I think it is very hard that a 1700 (and more) chooses just that.


[D]2r2k2/1p2bpp1/q6p/3pPp2/1p1P4/1P6/P2QbPPP/R1B1N1K1 b - - 0 25


Best Regards

Hi Maurizio,
I think Kg8 is a quiet move/tempo.
It's perhaps obvious for chess engines because it increases king safety (pawn shield), so you may be right that it's suspicious.
A human can play that move too, however. Judging whether one is cheating after one game is difficult.

[Olivier Deville]

28.... Qxa2 cannot possibly be seen by a 1700 FIDE rated player unless he had engine assistance, as a player of that level cannot normally see the tactics that win. If it was a one of two move tactic then I can agree but you need to see that the resulting attack is good for black.

If black were genuinely human then the rest of his games should be of a high level and he should be FIDE 2200+ not 1700. I would presume OTB he wouldn't have the "resources" available to him when he played this game.

I tend to disagree. As I wrote, this is a simple capture sequence. Some 1500, 1600, 1700 players can see it, some can't. So you can't say that only stronger players are able to see this type of combination.

I could try to argue about the details but my basic statement is you can't know what human players see and what they don't see. We are not talking about a sequence of difficult quiet moves here. The only one is the final move Be4, and I believe it is easy to see for some players. Mostly younger players will have less problems with that type of combination.

Sven

Sven

If you need to know, this player is over 40.

Here is another game he played in the same tournament. He was having white pieces and he obviously played all the moves by himself in this game. His style of play is very meek and prudent and this is why I do not believe he is able to find the winning exchange sacrifice. He actually offered a draw in a winning position.

The player who is playing black is around 1500. Please compare the two games...

1. d4 d5 2. Nf3 c6 3. g3 Nd7 4. Bg2 Ngf6 5. O-O g6 6. Bd2 Bg7 7. c3 h5 8. h4 Nf8 9. Bg5 N6h7 10. Nbd2 Nxg5 11. Nxg5 f6 12. Ngf3 Nh7 13. e4 g5 14. exd5 cxd5 15. Qa4+ Bd7 16. Qb3 Bc6 17. Qc2 Kf7 18. Rfe1 Bd7 19. hxg5 fxg5 20. Ne5+ Bxe5 21. Rxe5 e6 22. Nf3 h4 23. Qd2 hxg3 24. fxg3 1/2-1/2

Olivier

[krusher]

^^ Yes that is proof enough that the player used some assistance in that game, it is too high a standard for 1700. I expected another sample of spectacular games but instead we see a meek player.

[michiguel]

But on the other hand i think there is a particular move that hardly can be from a 1700: 25...Kg8.

I personally see nothing special about Kg8.
Black bludered with 28...Qxb4 as has been written already.
Qxa2 is obvious - black can't capture it because of Rxc1#
However the tactics behind 28...Qxa2 then later followed by 32...Be4 threatening a checkmate, not sure.
Can a 1700 player see it? (much stronger than me btw I don't know I'm very weak OTB.
Perhaps black was just lucky - can happen.

Hi Martin,

just because there's nothing special in 25....Kg8 it is a very suspicious move.

Kg8 is a move with a simple logic. Black wants to play Bg5, which is very tempting for 1700 player. However, it is obvious that is not good because Qxb4+. So, it is not surprising that black will take the king away, so Qxb4 won't be check after Bg5.

All black moves are straightforward. The sequence Rxc1, Bxe3 and Be4 is not impossible for a 1700 player. I have seen this type of combinations many times. Everything else is very plain.

Miguel

According to Houdini 2.0c here Black has at least 15 (!) moves scoring from -0.13 to +0.23 (depth 24), and black found just the best move, an apparently innocent move like Kg8, the move preferred by Houdini. I think it is very hard that a 1700 (and more) chooses just that.


[D]2r2k2/1p2bpp1/q6p/3pPp2/1p1P4/1P6/P2QbPPP/R1B1N1K1 b - - 0 25


Best Regards

[MM]

28.... Qxa2 cannot possibly be seen by a 1700 FIDE rated player unless he had engine assistance, as a player of that level cannot normally see the tactics that win. If it was a one of two move tactic then I can agree but you need to see that the resulting attack is good for black.

If black were genuinely human then the rest of his games should be of a high level and he should be FIDE 2200+ not 1700. I would presume OTB he wouldn't have the "resources" available to him when he played this game.

I tend to disagree. As I wrote, this is a simple capture sequence. Some 1500, 1600, 1700 players can see it, some can't. So you can't say that only stronger players are able to see this type of combination.

I could try to argue about the details but my basic statement is you can't know what human players see and what they don't see. We are not talking about a sequence of difficult quiet moves here. The only one is the final move Be4, and I believe it is easy to see for some players. Mostly younger players will have less problems with that type of combination.

Sven

Sven

If you need to know, this player is over 40.

Here is another game he played in the same tournament. He was having white pieces and he obviously played all the moves by himself in this game. His style of play is very meek and prudent and this is why I do not believe he is able to find the winning exchange sacrifice. He actually offered a draw in a winning position.

The player who is playing black is around 1500. Please compare the two games...

1. d4 d5 2. Nf3 c6 3. g3 Nd7 4. Bg2 Ngf6 5. O-O g6 6. Bd2 Bg7 7. c3 h5 8. h4 Nf8 9. Bg5 N6h7 10. Nbd2 Nxg5 11. Nxg5 f6 12. Ngf3 Nh7 13. e4 g5 14. exd5 cxd5 15. Qa4+ Bd7 16. Qb3 Bc6 17. Qc2 Kf7 18. Rfe1 Bd7 19. hxg5 fxg5 20. Ne5+ Bxe5 21. Rxe5 e6 22. Nf3 h4 23. Qd2 hxg3 24. fxg3 1/2-1/2

Olivier

Hi Olivier,

i understand your doubts but not because what you call ''sacrifice'', that i think it is possible to see for a 1700 and perhaps even lower rated, but because two different factors:
the computer style move 25....Kg8 and the fact that black made zero positional mistakes and zero tactical mistakes in the whole game.

Yes, one may say that black was better and the position was relatively easy to play but the fact of no mistakes remains (we're talking about a 1700).

As regards the 2nd game you posted, honestly it seems, according to Houdini 2.0c, that white didn't make big blunders but was clearly not so smart in several moves, especially in this position:

[D]r1bqk2r/pp2p1bn/5p2/3p2pp/3P3P/2P2NP1/PP1N1PB1/R2Q1RK1 w kq - 0 15

Here white has hxg5 that gives +0.92 but played Queen a4+ ?! (+0.69) but i don't see the sense of it because after Bd7, Qb3, Bc6 i wonder what white has gained to give check...

Best Regards

[MM]

But on the other hand i think there is a particular move that hardly can be from a 1700: 25...Kg8.

I personally see nothing special about Kg8.
Black bludered with 28...Qxb4 as has been written already.
Qxa2 is obvious - black can't capture it because of Rxc1#
However the tactics behind 28...Qxa2 then later followed by 32...Be4 threatening a checkmate, not sure.
Can a 1700 player see it? (much stronger than me btw I don't know I'm very weak OTB.
Perhaps black was just lucky - can happen.

Hi Martin,

just because there's nothing special in 25....Kg8 it is a very suspicious move.

Kg8 is a move with a simple logic. Black wants to play Bg5, which is very tempting for 1700 player. However, it is obvious that is not good because Qxb4+. So, it is not surprising that black will take the king away, so Qxb4 won't be check after Bg5.

All black moves are straightforward. The sequence Rxc1, Bxe3 and Be4 is not impossible for a 1700 player. I have seen this type of combinations many times. Everything else is very plain.

Miguel

According to Houdini 2.0c here Black has at least 15 (!) moves scoring from -0.13 to +0.23 (depth 24), and black found just the best move, an apparently innocent move like Kg8, the move preferred by Houdini. I think it is very hard that a 1700 (and more) chooses just that.


[D]2r2k2/1p2bpp1/q6p/3pPp2/1p1P4/1P6/P2QbPPP/R1B1N1K1 b - - 0 25


Best Regards

Hi Miguel, yes your analysis is right, King g8 with the idea to play bishop g5 so indeed that move is less ''computer move'' than what it seemed.

Best Regards

[Olivier Deville]

28.... Qxa2 cannot possibly be seen by a 1700 FIDE rated player unless he had engine assistance, as a player of that level cannot normally see the tactics that win. If it was a one of two move tactic then I can agree but you need to see that the resulting attack is good for black.

If black were genuinely human then the rest of his games should be of a high level and he should be FIDE 2200+ not 1700. I would presume OTB he wouldn't have the "resources" available to him when he played this game.

I tend to disagree. As I wrote, this is a simple capture sequence. Some 1500, 1600, 1700 players can see it, some can't. So you can't say that only stronger players are able to see this type of combination.

I could try to argue about the details but my basic statement is you can't know what human players see and what they don't see. We are not talking about a sequence of difficult quiet moves here. The only one is the final move Be4, and I believe it is easy to see for some players. Mostly younger players will have less problems with that type of combination.

Sven

Sven

If you need to know, this player is over 40.

Here is another game he played in the same tournament. He was having white pieces and he obviously played all the moves by himself in this game. His style of play is very meek and prudent and this is why I do not believe he is able to find the winning exchange sacrifice. He actually offered a draw in a winning position.

The player who is playing black is around 1500. Please compare the two games...

1. d4 d5 2. Nf3 c6 3. g3 Nd7 4. Bg2 Ngf6 5. O-O g6 6. Bd2 Bg7 7. c3 h5 8. h4 Nf8 9. Bg5 N6h7 10. Nbd2 Nxg5 11. Nxg5 f6 12. Ngf3 Nh7 13. e4 g5 14. exd5 cxd5 15. Qa4+ Bd7 16. Qb3 Bc6 17. Qc2 Kf7 18. Rfe1 Bd7 19. hxg5 fxg5 20. Ne5+ Bxe5 21. Rxe5 e6 22. Nf3 h4 23. Qd2 hxg3 24. fxg3 1/2-1/2

Olivier

Hi Olivier,

i understand your doubts but not because what you call ''sacrifice'', that i think it is possible to see for a 1700 and perhaps even lower rated, but because two different factors:
the computer style move 25....Kg8 and the fact that black made zero positional mistakes and zero tactical mistakes in the whole game.

Yes, one may say that black was better and the position was relatively easy to play but the fact of no mistakes remains (we're talking about a 1700).

As regards the 2nd game you posted, honestly it seems, according to Houdini 2.0c, that white didn't make big blunders but was clearly not so smart in several moves, especially in this position:

[D]r1bqk2r/pp2p1bn/5p2/3p2pp/3P3P/2P2NP1/PP1N1PB1/R2Q1RK1 w kq - 0 15

Here white has hxg5 that gives +0.92 but played Queen a4+ ?! (+0.69) but i don't see the sense of it because after Bd7, Qb3, Bc6 i wonder what white has gained to give check...

Best Regards

Interestingly, Fritz 9 likes 15.Qa4+ in that second game...

Olivier

[MM]

28.... Qxa2 cannot possibly be seen by a 1700 FIDE rated player unless he had engine assistance, as a player of that level cannot normally see the tactics that win. If it was a one of two move tactic then I can agree but you need to see that the resulting attack is good for black.

If black were genuinely human then the rest of his games should be of a high level and he should be FIDE 2200+ not 1700. I would presume OTB he wouldn't have the "resources" available to him when he played this game.

I tend to disagree. As I wrote, this is a simple capture sequence. Some 1500, 1600, 1700 players can see it, some can't. So you can't say that only stronger players are able to see this type of combination.

I could try to argue about the details but my basic statement is you can't know what human players see and what they don't see. We are not talking about a sequence of difficult quiet moves here. The only one is the final move Be4, and I believe it is easy to see for some players. Mostly younger players will have less problems with that type of combination.

Sven

Sven

If you need to know, this player is over 40.

Here is another game he played in the same tournament. He was having white pieces and he obviously played all the moves by himself in this game. His style of play is very meek and prudent and this is why I do not believe he is able to find the winning exchange sacrifice. He actually offered a draw in a winning position.

The player who is playing black is around 1500. Please compare the two games...

1. d4 d5 2. Nf3 c6 3. g3 Nd7 4. Bg2 Ngf6 5. O-O g6 6. Bd2 Bg7 7. c3 h5 8. h4 Nf8 9. Bg5 N6h7 10. Nbd2 Nxg5 11. Nxg5 f6 12. Ngf3 Nh7 13. e4 g5 14. exd5 cxd5 15. Qa4+ Bd7 16. Qb3 Bc6 17. Qc2 Kf7 18. Rfe1 Bd7 19. hxg5 fxg5 20. Ne5+ Bxe5 21. Rxe5 e6 22. Nf3 h4 23. Qd2 hxg3 24. fxg3 1/2-1/2

Olivier

Hi Olivier,

i understand your doubts but not because what you call ''sacrifice'', that i think it is possible to see for a 1700 and perhaps even lower rated, but because two different factors:
the computer style move 25....Kg8 and the fact that black made zero positional mistakes and zero tactical mistakes in the whole game.

Yes, one may say that black was better and the position was relatively easy to play but the fact of no mistakes remains (we're talking about a 1700).

As regards the 2nd game you posted, honestly it seems, according to Houdini 2.0c, that white didn't make big blunders but was clearly not so smart in several moves, especially in this position:

[D]r1bqk2r/pp2p1bn/5p2/3p2pp/3P3P/2P2NP1/PP1N1PB1/R2Q1RK1 w kq - 0 15

Here white has hxg5 that gives +0.92 but played Queen a4+ ?! (+0.69) but i don't see the sense of it because after Bd7, Qb3, Bc6 i wonder what white has gained to give check...

Best Regards

Interestingly, Fritz 9 likes 15.Qa4+ in that second game...

Olivier

I think that perhaps you are right although, of course, i don't have the absolute certainty.

Best Regards

[Kyodai]

For me 18.-Kf8 is a very strange, non-human kind of move.
My reaction was like "Hey what is this??" Quick check showed that this move was prefered by the loaded engine....

Hmm... never in my life I would have played such a move...