Once more into the breach...
Lead again by our great and intrepid dictator Plebusan, team Current_Affairs this week begins a new assault on the under-2000 section in Teamleague 38. This season sees the welcome return of a seasoned warrior in chestutr, the recruitment of new talent in gambiitti, and the scalping of former Teamleague supremo HyperMagnus to play our 1st board! Here's the full line-up:
1. HyperMagnus (2066)
2. Mapleleaf (1882)
3. gambiitti (1829)
4. Plebusan (1783)
5. SimianChatter (1758)
6. chestutr (1763)
Naturally enough you'll be surprised at my call-up to the team after my +1-10=0 performance in the previous two seasons, instead of being dragged out the back of channel 41 and shot (it would have been a mercy killing) - as first reserve I should get a crack at some 1800-ish opposition without our esteemed leader being tempted to chance me on board 1 or 2 again against the 2000-2100's.
I've had a bit of a break from FICS, Chess, Blogging, and work over the Christmas - New Year period, but it hasn't taken much to get back into it all what with the Corus Chess Festival now in full swing, and bills to pay...
Friday, January 23, 2009
Wednesday, January 7, 2009
Mikhail Tal And The Machines
There was a point, or pet theory at least, that I had intended to make in the last post. It involved quoting from a table I once saw out there in Internetland that showed the results of passing all the World Champions' games through a strong Chess engine and finding the percentage of coincidence between each champion's moves and the engine's first choice. For all the joys of Google, do you think I can find the damn thing when I want it?
From memory (I guess I'll update this if I stumble across the data I've misplaced...) pretty much all the champions in modern history played the "Fritz move" 80% +/-5% of the time. One interesting thing about this table that seemed to have a lot of people flumoxed was that Tal's coincident percentage was about the same as everyone else's - not the highest, but certainly not the lowest either. Tal by his own admission played many "unsound" sacrifices!
So the story goes, in the post mortem to one of his games, a young Garry Kasparov showed a sacrifice he had wanted to play but said he couldn't calculate all the consequences. "My boy, first you sacrifice, then you calculate!" was Tal's response.
As with any great magician, we become so dazzled by Tal's magic that we're distracted from noticing his consumate technique - the decoy tactical motif taken to a new level. It is not so often that Tal's opening knowledge and endgame technique are commented on, mundane as they are in the shadow of his middlegame wizardry. Yet noone becomes World Champion without total mastery of these mechanics of the game in addition to their stylistic expression.
One thing that the game in the last post shows - granted it's a very small data sample, but don't let that get in the way of a good story - is that it was Crafty trying to find Tal's moves, not Tal trying to find the machine's, and Crafty needed help! Crafty always came round to Tal's point of view eventually, but it had to be taken further down the game tree to realise that the wild attack and sacrifices were good for more than a draw.
"First I move my pieces to the centre of the board. Then I sacrifice them." - Mikhail Tal.
Let's interpret this statement in the context of Tal's high coincidence with computer moves. He begins the game with solid opening theory. Then he makes a sacrifice that, for the purposes of this argument we'll assume to be "unsound". His opponents can do one of two things. They can play sound moves and refute the sacrifice, or they can fail to find the defense - play unsound moves themselves - and get splattered. My 2700 rated version of Crafty falls into the second category - at least under tournament conditions with limited calculating time!
So how is Tal's "Fritz coincidence" so high? He only plays one unsound move per game, a very small minus percentage! The rest of his moves are perfectly sound, either more correct sacrifices in accordance with the position, or falling back on his World Champion class technique if the game steers towards an ending, or didn't permit even him to make sacrifices in the first place.
From memory (I guess I'll update this if I stumble across the data I've misplaced...) pretty much all the champions in modern history played the "Fritz move" 80% +/-5% of the time. One interesting thing about this table that seemed to have a lot of people flumoxed was that Tal's coincident percentage was about the same as everyone else's - not the highest, but certainly not the lowest either. Tal by his own admission played many "unsound" sacrifices!
So the story goes, in the post mortem to one of his games, a young Garry Kasparov showed a sacrifice he had wanted to play but said he couldn't calculate all the consequences. "My boy, first you sacrifice, then you calculate!" was Tal's response.
As with any great magician, we become so dazzled by Tal's magic that we're distracted from noticing his consumate technique - the decoy tactical motif taken to a new level. It is not so often that Tal's opening knowledge and endgame technique are commented on, mundane as they are in the shadow of his middlegame wizardry. Yet noone becomes World Champion without total mastery of these mechanics of the game in addition to their stylistic expression.
One thing that the game in the last post shows - granted it's a very small data sample, but don't let that get in the way of a good story - is that it was Crafty trying to find Tal's moves, not Tal trying to find the machine's, and Crafty needed help! Crafty always came round to Tal's point of view eventually, but it had to be taken further down the game tree to realise that the wild attack and sacrifices were good for more than a draw.
"First I move my pieces to the centre of the board. Then I sacrifice them." - Mikhail Tal.
Let's interpret this statement in the context of Tal's high coincidence with computer moves. He begins the game with solid opening theory. Then he makes a sacrifice that, for the purposes of this argument we'll assume to be "unsound". His opponents can do one of two things. They can play sound moves and refute the sacrifice, or they can fail to find the defense - play unsound moves themselves - and get splattered. My 2700 rated version of Crafty falls into the second category - at least under tournament conditions with limited calculating time!
So how is Tal's "Fritz coincidence" so high? He only plays one unsound move per game, a very small minus percentage! The rest of his moves are perfectly sound, either more correct sacrifices in accordance with the position, or falling back on his World Champion class technique if the game steers towards an ending, or didn't permit even him to make sacrifices in the first place.
Monday, January 5, 2009
Tactics Analysis - Tal vs Uhlmann, Moscow 1971
Today we're going to start looking at some master games, with the main idea of identifying as many tactical motifs as possible in them (rather than attempting a 'comprehensive' analysis at this stage). Who better to begin with then than Mikhail Tal - let's try and see if we can spot where he uses 'smoke and mirrors' and where he has a solid foundation for his 'wild' attacks.
We'll start at the point that things get really interesting, 12. Nf5. Black has grabbed a pawn leaving his King in the centre, his Black squares weak, and a couple of tempi behind in development.
Tal vs Uhlmann, Moscow 1971
Position after 12. Nf5
This Knight is a true "Trojan Horse"; it has been left as a gift just outside the citadel and it's capture flings open the gates for the entry of the attacking army. The motif in our vernacular is clearance of the e-file.
A computer should be ideal for analysing such a highly tactical situation, so it's interesting that Crafty gives this position about -2.5 (in Black's favour) at depth 10, but suddenly swings to +0.4 at depth 11. After 13. Re1+ (Crafty prefered an immediate 13. Qd6) it's back to -2, and it's not until depth 15 that it starts to see an advantage for White!
After 13. ... Nge7 the absolute pin on e7 and half-pin by the Bb5 are exploited by 14. Rxe7+ Nxe7 now Bd7 is pinned and (more importantly) barraged 15. Qxd7+ barraging Ne7 15. ... Kf8 16. Bxe7+. 13. ... Kf8 14. Qd6+ exploiting the weak black-coloured entry square leads to the same ideas, so Be6 is forced.
Tal vs Uhlmann, Moscow 1971
Position after 14. Qd6
Now the Black pieces are almost wholly immobilised. The King has a noose around His neck. There are absolute pins on Nc6 and Be6. Ng8 blocks Rh8 defending mate at e7. 14. ... Qxc2 15. Rac1 x-rays Nc6, a barrage allowing White to exploit the unprotected Ra8 and/or mate starting with 16. Rxc6 (i.e. 16. ... a6 17. Rc8 double check and mate), and other Queen moves also unprotect c6 permitting Bxc6+ immediately.
14. ... Rd8 and 14. ... Rb8 can be captured on the spot, again due to the absolute pin on Nc6, while 14. ... Rc8 15. Rad1 principally threatening 16. Qd8+ Rxd8 17. Rxd8# and Black can resign or play 15. ... Qxe1+ giving up a lot of material.
Of the available Pawn moves, Black chooses 14. ... a6 attempting to break the stranglehold by challenging the absolute pin on c6. At this point, it takes Crafty until depth 13 to see that White is not losing (giving 0.00), and perhaps more interestingly gives the game continuation to the end and beyond with white having only +0.5. We shall have to see...
White's forces, save for Ra1, are now at their maximum potential, and the fire needs some more fuel! If 15. Rad1 Black gets enough material for the Queen after 15. ... Qxe1+ and should be able to consolidate and win. Tal takes a new tack with 15. Bd2 Qxc2 16. Bb4.
The absolute pin on c6 is sacrificed for the final onslaught, a deep penetration at f8 with an x-ray attack on the unprotected Ra8.
Tal vs Uhlmann, Moscow 1971
Final position after 19. Qxa8
Here Black resigned, and in view of Crafty's assessment (after 14. ... a6), let's try to understand why.
First, note that the Bishop is immune to capture due to mate in 2 by Qd8+ and Qd6#. Black presently has a slight material advantage of B+N+2P vs R, but some of this will have to be returned to stave off a mating attack. White's ideas to continue the attack revolve around Ba5+ (trying to decoy the Knight to the mate in 2 threat again), but here ... b6 is a defense that will make the win a grind, and Rac1 - again with the absolute pin on the Knight! The Rac1 idea is why the e-Rook was used at move 18 (the "which Rook?" problem).
The black-squared Bishop will again be redeployed via c3 to a new line of attack, probably after provoking ... b6 as above to undermine the protection of c6.
Starting it's analysis at the final position on my fairly fast PC, it takes Crafty around 15 minutes to get to depth 13 and decide that White really does have a winning advantage (+1.9). At depth 14 (after nearly 30 minutes analysis) it's at +2.13 giving the line 19. ... Qe4 20. Rac1 Bd5 21. Ba5+ Kd6 22. f3 Qe3+ 23. Kh1 Nxa5 24. Qxa5 Nf6 25. Qc7+ Ke6 26. Re1 f4 27. Qxf4 Qxe1+ 28. Rxe1+ Kd7 29. Qg5 Rg8 30. Qd2.
Black is trying to build a shelter and run his King to safety, but it's still under constant harassment. Whether the players saw this over the board or simply had an intuition of the position's potential, there's not many who would relish trying to defend it against Tal.
We'll start at the point that things get really interesting, 12. Nf5. Black has grabbed a pawn leaving his King in the centre, his Black squares weak, and a couple of tempi behind in development.
Tal vs Uhlmann, Moscow 1971Position after 12. Nf5
This Knight is a true "Trojan Horse"; it has been left as a gift just outside the citadel and it's capture flings open the gates for the entry of the attacking army. The motif in our vernacular is clearance of the e-file.
A computer should be ideal for analysing such a highly tactical situation, so it's interesting that Crafty gives this position about -2.5 (in Black's favour) at depth 10, but suddenly swings to +0.4 at depth 11. After 13. Re1+ (Crafty prefered an immediate 13. Qd6) it's back to -2, and it's not until depth 15 that it starts to see an advantage for White!
After 13. ... Nge7 the absolute pin on e7 and half-pin by the Bb5 are exploited by 14. Rxe7+ Nxe7 now Bd7 is pinned and (more importantly) barraged 15. Qxd7+ barraging Ne7 15. ... Kf8 16. Bxe7+. 13. ... Kf8 14. Qd6+ exploiting the weak black-coloured entry square leads to the same ideas, so Be6 is forced.
Tal vs Uhlmann, Moscow 1971Position after 14. Qd6
Now the Black pieces are almost wholly immobilised. The King has a noose around His neck. There are absolute pins on Nc6 and Be6. Ng8 blocks Rh8 defending mate at e7. 14. ... Qxc2 15. Rac1 x-rays Nc6, a barrage allowing White to exploit the unprotected Ra8 and/or mate starting with 16. Rxc6 (i.e. 16. ... a6 17. Rc8 double check and mate), and other Queen moves also unprotect c6 permitting Bxc6+ immediately.
14. ... Rd8 and 14. ... Rb8 can be captured on the spot, again due to the absolute pin on Nc6, while 14. ... Rc8 15. Rad1 principally threatening 16. Qd8+ Rxd8 17. Rxd8# and Black can resign or play 15. ... Qxe1+ giving up a lot of material.
Of the available Pawn moves, Black chooses 14. ... a6 attempting to break the stranglehold by challenging the absolute pin on c6. At this point, it takes Crafty until depth 13 to see that White is not losing (giving 0.00), and perhaps more interestingly gives the game continuation to the end and beyond with white having only +0.5. We shall have to see...
White's forces, save for Ra1, are now at their maximum potential, and the fire needs some more fuel! If 15. Rad1 Black gets enough material for the Queen after 15. ... Qxe1+ and should be able to consolidate and win. Tal takes a new tack with 15. Bd2 Qxc2 16. Bb4.
The absolute pin on c6 is sacrificed for the final onslaught, a deep penetration at f8 with an x-ray attack on the unprotected Ra8.
Tal vs Uhlmann, Moscow 1971Final position after 19. Qxa8
Here Black resigned, and in view of Crafty's assessment (after 14. ... a6), let's try to understand why.
First, note that the Bishop is immune to capture due to mate in 2 by Qd8+ and Qd6#. Black presently has a slight material advantage of B+N+2P vs R, but some of this will have to be returned to stave off a mating attack. White's ideas to continue the attack revolve around Ba5+ (trying to decoy the Knight to the mate in 2 threat again), but here ... b6 is a defense that will make the win a grind, and Rac1 - again with the absolute pin on the Knight! The Rac1 idea is why the e-Rook was used at move 18 (the "which Rook?" problem).
The black-squared Bishop will again be redeployed via c3 to a new line of attack, probably after provoking ... b6 as above to undermine the protection of c6.
Starting it's analysis at the final position on my fairly fast PC, it takes Crafty around 15 minutes to get to depth 13 and decide that White really does have a winning advantage (+1.9). At depth 14 (after nearly 30 minutes analysis) it's at +2.13 giving the line 19. ... Qe4 20. Rac1 Bd5 21. Ba5+ Kd6 22. f3 Qe3+ 23. Kh1 Nxa5 24. Qxa5 Nf6 25. Qc7+ Ke6 26. Re1 f4 27. Qxf4 Qxe1+ 28. Rxe1+ Kd7 29. Qg5 Rg8 30. Qd2.
Black is trying to build a shelter and run his King to safety, but it's still under constant harassment. Whether the players saw this over the board or simply had an intuition of the position's potential, there's not many who would relish trying to defend it against Tal.
Friday, January 2, 2009
Holiday Puzzles - Solutions!
It's time we collectively slap our foreheads and cry "Bombaclot!".
Working backwards for no better reason than that's the way I decided to do it, here are the solutions to the Holiday Puzzles.
Puzzle #6
After 1. Bg2+ d5#, it's Professor Black who wins and no amount of philosophising about the en passant rule will change the result or reveal God's phone number. If you still don't believe me you can read about it on FIDE's web site.
Puzzle #5
The easy part - Black's last move must have been ... Ka7-a8. Slightly trickier, White's only possible move before this was Nb6-a8 discovered check (with h2 blocked, the Bishop has no other way to legally be there). So technically Black's last move (for full points) was ... Kxa8.
Puzzle #4
1. Any legal move, Any legal move
2. Any, Any
3. Any, Any
4. Any, Any
5. Any, Any
6. Any, Any
7. d7# (the only legal move!)
This genre of problem is called a "no-brainer", because Chess is a Zugzwang (move-bound) game, both sides MUST move alternately, and in this position whatever choice either side makes, it must be mate on move 7... I hope you didn't spend too long on it!
Puzzle #3
Ah, the "mate-in-zero"... the clue was outside the board - it's the only diagram I've published on this blog without the board co-ordinates showing. Flip the board around and the pawn on *f4* mates the Black King on *e5*. I know, you hate me for that one. I hate myself for using a trick that cheap too.
Puzzle #2
There's only one way to play half a move in chess. We took this photograph after White had played Ke1-c1, and before he completed Queen-side castling with Ra1-d1#. Please don't get mad with me, I only work here...
Puzzle #1
This one's a gentle introduction to the 'proof game' genre of Chess problems. I promised no tricks, and I stand by that! But the Knight on b8 won't tell you it started life as the King's Knight on g8.
1. Nf3, d5
2. Ne5, Nf6
3. Nc6, Nfd7
4. Nxb8, Nxb8
No-one said they had to be sensible moves!
Working backwards for no better reason than that's the way I decided to do it, here are the solutions to the Holiday Puzzles.
Puzzle #6
After 1. Bg2+ d5#, it's Professor Black who wins and no amount of philosophising about the en passant rule will change the result or reveal God's phone number. If you still don't believe me you can read about it on FIDE's web site.
Puzzle #5
The easy part - Black's last move must have been ... Ka7-a8. Slightly trickier, White's only possible move before this was Nb6-a8 discovered check (with h2 blocked, the Bishop has no other way to legally be there). So technically Black's last move (for full points) was ... Kxa8.
Puzzle #4
1. Any legal move, Any legal move
2. Any, Any
3. Any, Any
4. Any, Any
5. Any, Any
6. Any, Any
7. d7# (the only legal move!)
This genre of problem is called a "no-brainer", because Chess is a Zugzwang (move-bound) game, both sides MUST move alternately, and in this position whatever choice either side makes, it must be mate on move 7... I hope you didn't spend too long on it!
Puzzle #3
Ah, the "mate-in-zero"... the clue was outside the board - it's the only diagram I've published on this blog without the board co-ordinates showing. Flip the board around and the pawn on *f4* mates the Black King on *e5*. I know, you hate me for that one. I hate myself for using a trick that cheap too.
Puzzle #2
There's only one way to play half a move in chess. We took this photograph after White had played Ke1-c1, and before he completed Queen-side castling with Ra1-d1#. Please don't get mad with me, I only work here...
Puzzle #1
This one's a gentle introduction to the 'proof game' genre of Chess problems. I promised no tricks, and I stand by that! But the Knight on b8 won't tell you it started life as the King's Knight on g8.
1. Nf3, d5
2. Ne5, Nf6
3. Nc6, Nfd7
4. Nxb8, Nxb8
No-one said they had to be sensible moves!
Compositions, Studies, Problems
Like many practical Chess players, I've never taken more than a passing interest in the art form of Chess compositions, those fiendish "Mate in X" type things. The reason is common to a lot of players; at some time we've seen a problem posed as "mate in 2", spent an hour or so searching for the solution, only to find the key move is some bizzare counter-intuitive absurdity that leaves us cold.
By now you'll have realised that the holiday puzzles I've presented are just that, apart from #1 which is a simpler example of the 'proof game' genre, the others are really Chess jokes. But a funny thing happened on the way to the theatre... while I was scouring my book collection and the Internet for suitable material I came across a couple of web sites that are outstanding introductions to understanding how compositions work.
The first of these will already be familiar to many and is penned by Tim Krabbe. It is an eclectic mix of historical Chess records, Chess oddities, and compositions - from the sort of jokes I have presented to serious and studious compositions from tournaments. Yes indeed, problem composers have their own tournaments for composing and solving, and Master titles are bestowed independently of 'over-the-board' titles.
The real find however, was the blog of Greek problem composer Alkinoos. The first major obstacle to penetrating the world of compositions is knowing their language. Just as in regular Chess we can identify within a position various strategic and tactical motifs, compositions too have their themes. Do you know what a Grimshaw Intersection is? Pawn Albinos and Pickaninnies? The difference between a pure mate and an ideal mate? Understanding these things gives you an insight into the mind of the composer, so you're not simply trying moves at random until you stumble onto the key.
In practical Chess we talk about mainlines and side variations, in compositions too there are phases of play which may or may not be present, and these help guide us through the tricks and traps the composer is illustrating in the position.
Where compositions have little practical value to the player of Chess - aside from encouraging the habit of thinking laterally - studies can have immense value. Composition positions are often quite irrational; ideally it can be shown they could arise from a series of legal moves but usually it's highly improbable that they would. Studies on the other hand, look like normal endgame positions. The task is usually given as "White to win / draw" without a set number of moves, and the solution will frequently unlock some secrets of that type of endgame.
If you have an interest in Chess problems, or (and especially if...!) you never have but would like to expand your horizons into this fascinating field, you can do far worse than to start at Alkinoos' "Hello" page and click through the "newer post" links at the bottom of each page for the best tutorial on problem solving I have seen.
Reti, 1921
White to play and draw
This study is a classic - famous to the point of being a cliche, but it is still about the best example of how Kings work in a Pawn ending.
By now you'll have realised that the holiday puzzles I've presented are just that, apart from #1 which is a simpler example of the 'proof game' genre, the others are really Chess jokes. But a funny thing happened on the way to the theatre... while I was scouring my book collection and the Internet for suitable material I came across a couple of web sites that are outstanding introductions to understanding how compositions work.
The first of these will already be familiar to many and is penned by Tim Krabbe. It is an eclectic mix of historical Chess records, Chess oddities, and compositions - from the sort of jokes I have presented to serious and studious compositions from tournaments. Yes indeed, problem composers have their own tournaments for composing and solving, and Master titles are bestowed independently of 'over-the-board' titles.
The real find however, was the blog of Greek problem composer Alkinoos. The first major obstacle to penetrating the world of compositions is knowing their language. Just as in regular Chess we can identify within a position various strategic and tactical motifs, compositions too have their themes. Do you know what a Grimshaw Intersection is? Pawn Albinos and Pickaninnies? The difference between a pure mate and an ideal mate? Understanding these things gives you an insight into the mind of the composer, so you're not simply trying moves at random until you stumble onto the key.
In practical Chess we talk about mainlines and side variations, in compositions too there are phases of play which may or may not be present, and these help guide us through the tricks and traps the composer is illustrating in the position.
Where compositions have little practical value to the player of Chess - aside from encouraging the habit of thinking laterally - studies can have immense value. Composition positions are often quite irrational; ideally it can be shown they could arise from a series of legal moves but usually it's highly improbable that they would. Studies on the other hand, look like normal endgame positions. The task is usually given as "White to win / draw" without a set number of moves, and the solution will frequently unlock some secrets of that type of endgame.
If you have an interest in Chess problems, or (and especially if...!) you never have but would like to expand your horizons into this fascinating field, you can do far worse than to start at Alkinoos' "Hello" page and click through the "newer post" links at the bottom of each page for the best tutorial on problem solving I have seen.
Reti, 1921White to play and draw
This study is a classic - famous to the point of being a cliche, but it is still about the best example of how Kings work in a Pawn ending.
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