Skype coaching session, 06 April 2020. Two Sunday coaching sessions are planned for April, on the dates: 19, 26. Time: all sessions will start at UTC 14:00, which is, BMT 15:00. The game discussed (45 moves) is given below with annotations, without annotations plus a supplementary section on the, "Impotent Pair". Re-structuring of the sessions now offers the option for guests to bring their own games for group discussion. Recordings of some previous coaching sessions can be found at: http://www.open-aurec.com/Skype/PaulBenson/PaulBenson.htm Paul Benson. * * * Annotated Game. White: Baron von der Lasa. Black: W. Hanstein. Event: Berlin 1839. Result: 1/2-1/2 in 45 moves. Opening: Philidor Defence, Philidor Counter-Gambit, C41. | Editorial. No FIDE Elo ratings available today. Doubtless there are websites out there who can work backwards through time to give approximations. Instead just consider that White here has beaten both Howard Staunton and Adolf Amderssen in matches. According to limited database, Black here has a record of 12 wins, 9 draws, 14 losses, with this opponent. How much organised chess was there back in 1839? Perhaps matches of city against city. Definitely individual challenges. And how much chess literature was there available in the shops? Perhaps these players learned to play chess in battle rather than settling down on the sofa in front of shelves of books on all aspects of chess. If so, we must admire how inventive they were back then, as the phrase goes today: "We are standing on the shoulders of giants." And here to start the notes off are a couple of examples of what they can do. H. Staunton - Baron von der Lasa, Brussels (Match) 1853, witnessed a see-saw kingside struggle: 1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. Qe2 Bd6 5. c3 O-O 6. O-O Re8 7. d3 h6 8. Nh4 Ne7 9. Bc4 c6 10. Qf3 Bc7 11. Bxh6 d5 12. Bb3 Bg4 13. Qg3 gxh6 14. h3 Kh7 15. hxg4 Rg8 16. Qf3 Nxg4 17. Qxf7+ Rg7 18. Qf3 Qd7 19. Qe2 Rf8 20. Nd2 Ng6 21. Nxg6 Rxg6 22. Nf3 Rgf6 23. Bd1 Rxf3 24. gxf3 Nh2 25. Kxh2 Rf4 26. Rg1 Rh4+ 27. Kg2 Qh3# 0-1. A nice demonstration of sacrificing to restrict an enemy king combined with mobilisation for the kill. W. Hanstein - Baron von der Lasa, 1843, produced some fine King's Gambiteering: 1. e4 e5 2. f4 exf4 3. Nf3 g5 4. Bc4 g4 5. Ne5 Qh4+ 6. Kf1 f3 7. gxf3 d5 8. Bxd5 Nf6 9. Bxf7+ Ke7 10. d4 Nc6 11. Bc4 g3 12. Ke2 Nxe4 13. Nc3 Nf2 14. hxg3 Qxg3 15. Rg1 Qxe5+ 16. dxe5 Nxd1 17. Bg5+ Kd7 18. Raxd1+ 1-0. Sometimes tactics, sometimes tactricks, but it worked. || 1. e4 e5 2. Nf3 d6 3. d4 f5 | Immediately injecting tension into the position. Calmer approaches are available, 3. ... exd4, 3. ... Nf6, 3. ... Nd7, are the top 3 choices on the limited database, other moves are played by black but do not score well. A more modern move order by black in the Philidor Defence might be, 1. ... d6, 2. ... Nf6, 3. ... Nbd7, 4. ... e5, with some quite interesting middlegames available if black can find the courage to play, 5. ... h6, and then, 6. ... g5. || 4. dxe5 | Also possible is, 4. exf5 Bxf5, but with only a handful of games on the limited database it is difficult to give judgement. A different approach is, 4. exf5 e4 5. Ng5 Bxf5 6. f3, immediately challenging the black centre. || 4. ... fxe4 | The only sensible response, black is about to build a pawn centre. || 5. Ng5 | White begins the, "Light-Square Fight", the black e4 pawn is attacked, it can easily be defended, but this only sets the scene for the initial skirmish. || 5. ... d5 | It is only move 5 completed and white already has a passed pawn, how many openings can do this? White to play can similarly continue with the, "Light-Square Fight". Clue: The central black pawns are restricting white pieces from using several light squares, has white a similar option available? || 6. e6 | Only move 6 played by white and there is a passed pawn standing quite safe, at least for the moment, on the 6th rank, how many openings can do this? White now has powerful threats of, Nf7, available as well as preventing the black c8 bishop from developing. || 6. ... Nh6 | Defending, there is an attacking option, 6. ... Bc5, when white should reply, 7. Nxe4, because, 7. ... dxe4 8. Qh5+ g6 9. Qxc5, but what about 7. Nf7, winning at least an exchange? Consider the following miniature. T. Barnes - P. Morphy, London (Casual game) 1958, showed that falling behind in development can place oneself in danger: 1. e4 e5 2. Nf3 d6 3. d4 f5 4. dxe5 fxe4 5. Ng5 d5 6. e6 Bc5 7. Nf7 Qf6 8. Be3 d4 9. Bg5 Qf5 10. Nxh8 Qxg5 11. Bc4 Nc6 12. Nf7 Qxg2 13. Rf1 Nf6 14. f3 Nb4 15. Na3 Bxe6 16. Bxe6 Nd3+ 17. Qxd3 exd3 18. O-O-O Bxa3 19. Bb3 d2+ 20. Kb1 Bc5 21. Ne5 Kf8 22. Nd3 Re8 23. Nxc5 Qxf1 24. Ne6+ Rxe6 0-1. Perhaps white, 14. f3, caused some unnecessary headaches,14. Qd2, or, 14. Nd2, give white an acceptable game, nevertheless, bold play by black throughout eventually gave rewards. || 7. c4 | Not many examples now, other moves have been tried, the common factor of very active play seems consistent no matter the variation, examine such a sample here. E. Mortensen (2423) - J. Hvenekilde (2267), Politiken Cup Copenhagen, 2001, went: 1. e4 e5 2. Nf3 d6 3. d4 f5 4. dxe5 fxe4 5. Ng5 d5 6. e6 Nh6 7. Nc3 c6 8. Be3 Qf6 9. Nxd5 cxd5 10. Bb5+ Nc6 11. Qxd5 Bb4+ 12. c3 Bxc3+ 13. bxc3 Qxc3+ 14. Kd1 Nf5 15. Rc1 Nxe3+ 16. fxe3 Qxe3 17. Rf1 1-0. Life in this opening system often seems to be short and brutal. || 7. ... Bb4+ 8. Nc3 | Probably the best. The disastrous, 8. Nd2 Qxg5, losing the g5 knight is not recommended. Instead, 8. Bd2 Qxg5 9. Bxb4 Bxe6, does not seem worth a pawn. || 8. ... d4 | Pinning and winning a piece, right? || 9. a3 | The standard way to avoid losing a pinned knight, expand with both queenside pawns if necessary, options of queenside pawn formation imbalances are are on offer. Black to play can start stirring it up. Clue: Interference is the name of the game. || 9. ... e3 | A doubler. Firstly, the white c1 bishop defence to the g5 knight has been blocked. Secondly, the option of, exf2+, exposing the white king is available. || 10. Qh5+ | Defending the white g5 knight and leaving black to decide how to handle the kingside. A different story would emerge after, 10. axb4 Qxg5 11. Qxd4 exf2+ 12. Qxf2 Qe5+ 13. Be2 Rf8, and black will soon pick off the white e6 pawn. || 10. ... g6 | With each player having a piece en prise on the queenside black decides to let a piece go on the kingside, there is method in this apparent madness. Moving the black king invites tactics, perhaps sound or perhaps not, some ideas run: (A). If, 10. ... Ke7 11. Nxh7 Rxh7 12. Bg5+, black will be losing the queen for 2 white minor pieces. (B). Or if, 10. ... Ke7 11. Nxh7 Kxe6 12. Ng5+ Ke7 13. Nxe4, the black king is still uncomfortable. (C). Or if, 10. ... Kf8 11. Nf7 Nxf7 12. Qxf7+ mate will not happen. (D). Or if, 10. ... Kf8 11. Nf7 Qe8 12. axb4 dxc3 13. Qc5+ Kg8 14. Nxh8, white has won an exchange. Of course, if black plays either, Ke7, or, Kf8, white does not have to go for kingside play. (E). Or if, 10. ... Ke7 11. fxe3 dxc3 12. axb4, the white king has no obvious discomfort, can the same be said for the black king? || 11. Qxh6 | With ideas of, 12. Qg7, or, 12. Nxh7, undermining the black g6 pawn. Black to play must have had in idea in mind when pushing, 9. ... e3, which allowed white, 10. Qh5+, leading to this position, but what? || 11. ... exf2+ | Black has a plan to reduce material to relieve the pressure around his own king. Fine, but perhaps the complete opposite, as many in the coaching group felt, that hunting the white king could have given rewards, some ideas run: (A). If, 11. ... dxc3 12. Qg7 cxb2+ 13. axb4 bxc1=Q+ 14. Rxc1 Qd2+ mate, the value of keeping a pawn on e3 is shown. (B). Or if, 11. ... dxc3 12. Qg7 cxb2+ 13. axb4 bxc1=Q+ 14. Ke2 Qdd1+ mate. (C). Or if, 11. ... dxc3 12. axb4 cxb2 13. Bxb2 Qd2+ mate. (D). Or if, 11. ... dxc3 12. axb4 cxb2 13. Ke2 bxa1=Q, black is a queen plus an exchange up. (E). Or if, 11. ... dxc3 12. axb4 cxb2 13. fxe3 bxa1=Q, black is a queen plus an exchange up. (F). Or if, 11. ... dxc3 12. Nf7 c2+ 13. axb4 Qd1+ mate, is unlikely to happen. Lastly, a couple of long lines which will have branch-points for white to find something else, but the general flavour of the strength of the black attack should be clear. (G). Or if, 11. ... dxc3 12. Nf7 c2+ 13. Ke2 Qd1+ 14. Kxe3 Bc5+ 15. Ke4 Qd4+ 16. Kf3 Qxf2+ 17. Ke4 Bxe6 18. Nxh8 Bf5+ 19. Ke5 Qd4+ mate. (H). Or if, 11. ... dxc3 12. Nf7 c2+ 13. Ke2 Qd1+ 14. Kxe3 Bc5+ 15. Kf4 Qd4+ 16. Kg5 Bxe6 17. Nxh8 Qg4+ 19. Kf6 Bd4+ mate, is rather neat. || 12. Kxf2 Bf8 | Black retreats the bishop from attack while placing an attack on the white h6 queen, meaning the white c3 knight can now be captured to equalise material. || 13. Qh3 | A doubler. Firsttly, the white e6 pawn is given an extra defence. Secondly, if black immediately captures with, 13. ... dxc3, white has, 14. Qxc3, hitting the black h8 rook which will shuffle, 14. ... Rg8, to be followed with, 15. Nxh7. || 13. ... Qf6+ | Black throws in a queen check in order to cover the c3 square, the black kingside will not be disrupted should white recapture on c3 with the queen. || 14. Qf3 | White offers a trade of queens, if black declines in some way then white simply moves the c3 knight and emerges a piece up. || 14. ... Qxf3+ 15. gxf3 | When a unit moves lines previously closed become open, this pawn back on g2 was preventing a useful white move. || 15. ... dxc3 16. Bh3 | The reason for capturing on f3 with the g-pawn is revealed, the e6 pawn needs over-protection as black can play, pawn h6, pushing the white g5 knight around. But surely white is forgetting about the black c3 pawn? Not really, white will be very happy if black goes down, 16. ... cxb2 17. Bxb2 Rg8 18. Rad1, when white has a 4 - 0 lead in developed units. || 16. ... Bc5+ 17. Kg2 Nc6 | Again black wisely chooses development over material, sooner or later white will feel forced into capturing, bxc3, creating 4 pawn islands. || 18. bxc3 | If white wishes to develop the c1 bishop then something must be done with the b2 pawn. This leaves white with a shattered queenside pawn formation, but "Weak Pawns", are only weak if they can be targeted, it requires black to coordinate piece activity against them. Instead, 18. b4 Bd4, just creates a headache on the c3 square, how is white to eliminate the black c3 pawn? || 18. ... Ne5 | "Weak Pawns", must be targeted, the white c4 pawn cannot be defended. Whoever has, "Weak Pawns", needs to get plenty of piece activity, trying to force the enemy pieces into defensive roles, meaning the, "Weak Pawns", do not actually need defending. || 19. Bf4 | Developing with an attack-tempo is always useful, even more so here as there is an x-ray attack placed on the black c7 pawn. || 19. ... Nxc4 | Defending is disastrous, some ideas run: (A). If, 19. ... Bd6 20. c5 Bxc5 21. Bxe5, black loses a knight for a pawn. (B). Or if, 19. ... Bd6 20. c5 Nd3 21. Bxd6 cxd6 22. cxd6 h6 23. d7+ Ke7 24. dxc8=Q Raxc8 25. Ne4 Nf4+, black gets the white e6 pawn but would be a piece down in the process. || 20. Bxc7 Ne3+ | Why is black declining capturing the white, "Weak Pawn", on the a3 square? Perhaps black fears white will have a strong position once the rooks centralise, and so instead chooses to control the d1 square. || 21. Kg3 | Walking into an x-ray attack is painful, 21. Kf2 Nc2+, picks off an exchange on a1 without any compensation for white. || 21. ... h5 | Black has ideas of further pushing the white king around, the threats are, 22. ... h4+ 23. Kf4 Nd5+, forking the white f4 king and unprotected c7 bishop, or, 22. ... h4+ 23. Kf2 Nd5+, again picking off the white c7 bishop. || 22. f4 | The f3 square is vacated for the white king. || 22. ... b6 | Intending, Bb7, claiming important light squares, g2, and, f3, around the white king. || 23. Ne4 | Targeting the black c5 bishop which if removed will give the white king a much easier life. Another way to challenge the black c5 bishop was, 23. Be5 Rf8 24. Bd4, which forces, 24. ... Bxd4 25. cxd4, and white has a better pawn structure than occurs in game. || 23. ... h4+ | Forcing the white king to make an awkward decision, onto which diagonal should he be pushed? || 24. Kf2 | White chooses to allow the black c5 bishop to have an x-ray attack. Instead stepping onto the light square diagonal, 24. Kf3 Bb7, and white must go through more manoeuvring to free the pinned white e4 knight. || 24. ... Nd5+ | Black goes for an indirect trade of bishops. This reduces the, "Active Piece Count", at white =2, black = 1, but matters are not so simple, white will have the easier options for rook development and the safer king. Instead black could have gone for material imbalance with, 24. ... Nc2+, some ideas run: (A). If, 24. ... Nc2+ 25. Nxc5 Nxa1 26. Rxa1 bxc5 27. Rd1 Bb7 28. Rd7, white has much activity plus a pawn for the exchange. (B). Or if, 24. ... Nc2+ 25. Nxc5 Nxa1 26. Rxa1 bxc5 27. Rd1 Ke7 28. Bd6+ Ke8 29. Bxc5, black has an exchange for 2 pawns but must find a safe way to develop. (C). Or if, 24. ... Nc2+ 25. Nxc5 Nxa1 26. Rxa1 bxc5 27. Rd1 Ke7 28. Bd6+ Kf6 29. Bxc5 Bxe6 30. Bd4+ Ke7 31. Bxe6 Kxe6 32. Bxh8 Rxh8, black would be a pawn down and would have to fight to get a draw. (D). Or if, 24. ... Nc2+ 25. Nxc5 Nxa1 26. Rxa1 bxc5 27. Rd1 Ke7 28. Bd6+ Kf6 29. Bxc5 Bxe6 30. Bd4+ Ke7 31. Bxe6 Rhd8 32. Re1, the white bishop pair plus passed c3 pawn give white an overpowering advantage. || 25. Nxc5 bxc5 | Black prefers to keep pressure on the white c3 and f4 pawns and so leaves the white c7 bishop alone. || 26. Be5 | Move 26 played by white and so far none of the 4 rooks have moved. A curious form of social distancing, all remaining 6 files apart? Or maybe the way they fought back in 1839, hammer around with a few pieces and when the battling begins to slow down, call up reinforcements? Thankfully today we know we should develop pieces quickly, the only problem is thinking we know better and choose to disobey. || 26. ... Rf8 | Doubly-attacking the white f4 pawn which is not easy to defend. || 27. Bg2 | White chooses to mix it up. Defending with, 27. Kf3 Bb7 28. Rhb1 Bc6, and the black c6 bishop x-ray attack through the black d5 knight must cost white something somewhere. || 27. ... Bxe6 | Black must lose material no matter what, the white g2 bishop pin on the black d5 knight is too powerful. There is however the scattered white pawns to take into account, perhaps black can find a means of wiping them all out? This would be drawn if all white has is a single piece, but it could be won if it is rook plus bishop against rook, depending on how restricted the defending king is. And while still a long way off, white must think of the, "Impotent Pair", of rook pawn plus single bishop, not of the same shade (dark / light) of the promotion square. Instead, 27. ... Bb7 28. c4, black can only choose whether to lose the d5 knight or the b7 bishop. Tactical Tool: "The power of the pin is to paralyse." || 28. c4 Nxf4 | About the only move to confuse matters. Black tries some tactics, again, if white loses too many pawns the extra material will be of limited or no value. || 29. Bxf4 | This will win a piece. Instead, 29. Bxa8 Nd3+ 30. Ke3 Nxe5, and black loses an exchange for a pawn. || 29. ... Rd8 | Obvious recapture fails, 29. Rxf4 30. Ke3, and both black rooks are en prise and there is no single move which can protect both. || 30. Bc6+ | Forcing the black king to a less favourable square. || 30. ... Ke7 | Stepping onto a dark square, black must now be aware of possibilities of white, Bg5+, losing an exchange, once the white king escapes the black f8 rook pin. Instead, 30. ... Kf7, blocks the action of the black f8 rook, when a piece down keep the remaining pieces as active as possible. || 31. Ke3 Rd4 | A tripler. Firstly, the dangers of white, Bg5+, winning an exchange are avoided. Secondly, a double-attack is placed on the white f4 bishop. Thirdly, a double-attack is placed on the white c4 pawn. Thoughts of an ending with the, "Impotent Pair", of rook pawn plus wrong shade of bishop must now be kept in mind, black must seek this situation, white must avoid it. || 32. Bg5+ Kd6 | Tempo-attack on the white c6 bishop. As pawns disappear the pieces have less, "Anchor-Points", to protect them, tactics can begin to emerge as tension mounts like an old-fashioned clock-spring is wound up. || 33. Be4 | Aiming itself at the unprotected black g6 pawn, black must surely be forced into protecting this, right? || 33. ... Ke5 | The black king claims a little central space while creating a double-attack on the white e4 bishop. There is no hurry to capture the white c4 pawn, it cannot be satisfactorily defended, so improve the position first before eliminating it. || 34. Bd3 | Avoiding, 34. Bxg6 Rg8, and white can only think of ways of getting the most for a piece, perhaps, 35. Bxh4 Rxg6, and the presence of opposite bishops will save either player should difficulties arise. || 34. ... Bxc4 35. Bxc4 | White chooses to trade bishops while the opportunity is present. The pairing of the, "Impotent Pair, is now set. The 3-step drawing method for black is: #1. Advance the kingside pawns in such a manner as to force the trade-off of the white h-pawn. #2. Trade off all remaining rooks. #3. While completing steps 1 and 2, make sure the king will always be able to occupy the a8 square. If the black king cannot get to a8 it is possible for white to promote the a-pawn despite the promotion square being light. For an example of the, "Impotent Pair", failing and succeeding consult the supplementary section. || 35. ... Rxc4 36. Rhe1 | Intending to meet, 36. ... Rc2, with, 37. Re2, protecting the all-important h2 pawn. || 36. ... Rd4 | Black has no real plan but must wait for white to do something and respond accordingly. || 37. Rad1 | White is preparing to trade down, the only protector to the black h4 pawn is the d4 rook, if white ever safely gets in, Bxh4, the h2 pawn is almost certainly guaranteed safety with, Bg3, at some point. Black now finds a neat way to stir matters up, but beware that with all pieces active and only a few pawns around there can be surprises to be found. || 37. ... Kf5 | Hoping white will fall for the tactrick. It is not easy to find anything better, white is beginning to simplify the position, so go for whatever trickies are available. || 38. Bh6 | An opportunity missed. The tactricks to be avoided were: (A). If, 38. Rxd4 cxd4+ 39. Kxd4 Kxg5, and it is white now a pawn down who is struggling to draw. (B). Or if, 38. Rf1+ Kxg5 39. Rxf8 Rxd1, white 2 pawns down should be losing this. (C). Or if, 38. Rf1+ Kxg5 39. Rxd4 cxd4+ 40. Kxd4 Rxf1, white is a rook plus pawn down. (D). Or if, 38. Rf1+ Kxg5 39. Rxd4 cxd4+ 40. Ke2 Rxf1 41. Kxf1 Kf4, the 2 extra black pawns will easily win. So white avoids the worst lines, but is there something wrong with the black position? Clue: Overloaded units must be exploited. White misses the surprising, 38. Bxh4, the ideas run: (E). If, 38. Bxh4 Rxh4 39. Rf1+ Kg5 40. Rxf8 Rxh2 41. Rg1+ Kh6 42. Rh8+ Kg7 43. Rxh2, white is 2 rooks up. (F). Or if, 38. Bxh4 Rxh4 39. Rf1+ Kxg5 40. Rxf8 Rxh2 41. Rg1+ Kh4 42. Rh8+ mate. (G). Or if, 38. Bxh4 Rxh4 39. Rf1+ Kxg5 40. Rxf8 Ra4 41. Rd3, white is a rook for 2 pawns up, careful technique should convert this. (H). Or if, 38. Bxh4 Rxh4 39. Rf1+ Rf4 40. Rxf4+ Kxg5 41. Rxf8+, white has 2 extra rooks for 2 pawns. This tactic works for white due to the overloaded nature of the black d4 rook, it must protect the h4 pawn and it must be able to play, Rxd1, should white fall into the, Rf1+, trap, it cannot do both. Black in the game starts trading down to achieve the desired aim. || 38. ... Re8+ 39. Kf3 Rxe1 40. Rxe1 g5 | The black kingside pawns have been permitted to start rolling, white now has extreme problems concerning keeping the h-pawn on the board. || 41. Bg7 | The bishop must get back into the game. || 41. ... g4+ 42. Kf2 | Despite being a piece up it is white who must be careful, this king move is designed to avoid difficulties. Black has 4 active units while the white forces are not coordinating. The spectre of the, "Impotent Pair", is also on the horizon. Instead, 42. Kg2 Rd2+ 43. Kg1 g3, exchanging by white leads to a draw while trying to win with, 44. h3 Rh2, loses the h3 pawn, white has created good losing chances. || 42. ... Rd2+ 43. Re2 | Again retreating with, 43. Kg1 g3, white must exchange pawns and the white king is worse than in the game continuation. Black to play has the opportunity to remove all doubts about the result of the game. || 43. ... g3+ 44. hxg3 hxg3+ 45. Kf1 | Clearly, 45. Kxg3 Rxe2, giving black the full point is not going to happen. || 45. ... Rxe2 Draw agreed, 1/2-1/2. | At club level there would be more mutual testing of the necessary knowledge to avoid defeat. The simplest drawing method for black is to run the king to a8 and shuffle as shown in the supplementary section below, the extra black pawns make no difference to the process. A bad mistake for black would be to try and win. Imagine the black king getting across to the h-file to support the advance of the g3 pawn, the idea is to win the white bishop. White will be happy to play along, perhaps shuffling, Bh6, landing on e3, covering g1. While black gets the king to h2 the white king will be heading for the black c5 pawn and then on to the a7 pawn. Black will indeed pick up the white bishop by promoting on g1, but all this takes time. It then comes down to whether the black king can get across to the queenside to achieve a draw by restricting the white king to the a-file. A few lines discussed during the session suggested white wins if black tries to promote the g3 pawn. Recognising when to accept playing for a win will give excellent losing chances can only come from endgame study or learning the hard way over the board followed by post-mortem analysis. || * * * ## Unannotated Game. White: Baron von der Lasa. Black: W. Hanstein. Event: Berlin 1839. Result: 1/2-1/2 in 45 moves. Opening: Philidor Defence, Philidor Counter-Gambit, C41. 1. e4 e5 2. Nf3 d6 3. d4 f5 4. dxe5 fxe4 5. Ng5 d5 6. e6 Nh6 7. c4 Bb4+ 8. Nc3 d4 9. a3 e3 10. Qh5+ g6 11. Qxh6 exf2+ 12. Kxf2 Bf8 13. Qh3 Qf6+ 14. Qf3 Qxf3+ 15. gxf3 dxc3 16. Bh3 Bc5+ 17. Kg2 Nc6 18. bxc3 Ne5 19. Bf4 Nxc4 20. Bxc7 Ne3+ 21. Kg3 h5 22. f4 b6 23. Ne4 h4+ 24. Kf2 Nd5 25. Nxc5 bxc5 26. Be5 Rf8 27. Bg2 Bxe6 28. c4 Nxf4 29. Bxf4 Rd8 30. Bc6+ Ke7 31. Ke3 Rd4 32. Bg5+ Kd6 33. Be4 Ke5 34. Bd3 Bxc4 35. Bxc4 Rxc4 36. Rhe1 Rd4 37. Rad1 Kf5 38. Bh6 Re8+ 39. Kf3 Rxe1 40. Rxe1 g5 41. Bg7 g4+ 42. Kf2 Rd2+ 43. Re2 g3+ 44. hxg3 hxg3+ 45. Kf1 Rxe2 Draw agreed, 1/2-1/2 * * * ## Supplementary Section - The, "Impotent Pair", Failure And Success. Failure - Position with white to move: White: Kf6, Bg2, Pa7, Ph2. Black: Kg8, Nc7. | There are several ways for white to win this, knowledge of the, "Impotent Pair", should drive white to find the winning idea. Here white is not aware of the problem ahead and charges in with the, "Obvious"... || 1. a8=Q+ | A hasty and sad mistake, it will now be drawn. The winning method is to advance the white king to attack the black c7 knight, a sample line runs: 1. Ke7 Kh8 2. Kd7, if the black knight moves the white a7 pawn promotes, if it stands still it falls, so white wins. In the game white has been too hasty to win material, believing the extra bishop plus pawn will automatically win. Knowledge of endgames drives strategic decisions over which units to keep and which to trade off. || 1. ... Nxa8 2. Bxa8 Kh8 3. Kg6 Kg8 4. h4 Kh8 5. h5 Kg8 | White now brings the a8 bishop back into play expecting a quick win. || 6. Be4 Kh8 7. Kh6 Kg8 8. Bh7+ Kh8 | It is now stalemate-in-waiting, white must break the pattern and try something else. || 9. Be4 Kg8 10. Bd5+ Kh8 | It is again stalemate-in-waiting, white must break the pattern. || 11. Bf3 Kg8 12. Kg6 Kh8 13. Kf7 Kh7 14. Kf8 Kh8 | White cannot force the king off the h8 square, there is no progress to be made, but just to prove it cannot be done... || 15. Kf7 Kh7 16. Kf6 Kh8 17. Kg6 Kg8 18. h6 Kh8 19. Be2 Kg8 20. h7+ Kh8 | White now has problems, the black king has again gained stalemate-in-waiting, the choices are: (A). If, 21. Kh6, stalemate. (B). Or if, 21. Kf7 Kxh7, draw, a king plus single bishop cannot force mate. (C). Or if, 21. Bb5, stalemate. || Success - Position with white to move: White: Kf4, Bd3, Ph6. Black: Kf7. | White has the necessary factors in place: #1. The h6 pawn controls the g7 square. #2. The bishop sits on the b1 - h7 diagonal. #3. The f4 king fights for the g5 square, black must not be allowed, Kg5, once white controls the necessary squares on the g-file. || 1. Bh7 | Counter-intuitive, blocking the advance of the passed pawn, but it is the correct way to win. The purpose of the bishop sitting on h7 is to combine with the h6 pawn to create the necessary, "Mini-Barrier", covering the squares, g6, g7, g8. || 1. ... Kf6 2. Kg4 | The black king cannot take the opposition with, 2. ... Kg6, as this is illegal, it must give way. || 2. ... Kf7 3. Kf5 Kf8 4. Kf6 Ke8 | The black king has lost the fight for the g7 square, several ways for white to promote the h6 pawn. || 5. Bg8 | Also winning is, 5. Kg7 Ke7 6. Bg6 Ke6 7. h7, and promotes. || 5. ... Kf8 6. h7 Ke8 7. h8=Q | White should quickly mate with the new queen plus bishop. In closing, black was given a favourable king position, Kf7, which forced white to work for the win. Had the white king been able to land very quickly on g7 it would be a simple win. || * * *