Skype coaching session, 23 February 2020. Note: Daylight saving time might be in operation in your time zone, check your calendar to be certain when 14:00 UTC occurs for you. 3 coaching sessions are planned for March on Sundays: 15, 22, at 14:00 UTC, which is 14:00 GMT. And Sunday: 29, at 14:00 UTC, which is 15:00 BST. The game discussed is given below with annotations and without annotations plus repeat annotations from 16 February notes up to white move 11. 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: V. Kotronias, 2524. Black: S. Estremera, 2339. Event: Rilton Cup (Stockholm) 2017-18. Opening: Petroff Defence, Classical Attack, C42. | Editorial. The result and number of moves have been deliberately withheld. Why? This game will produce a fascinating endgame where knowing the result might cloud opinion as play proceeds. Of course, slipping to the end of the game score will provide both result and number of moves. It is recommended for full enjoyment plus potential learning that this remains unknown right to the end of the game. || 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bf5 7. O-O Be7 8. c4 dxc4 9. Bxc4 O-O 10. Re1 Nd6 | The game in the coaching session of 16 February 2020 reached this position. For comments on the opening moves up to this point visit Section 3 below. || 11. Bb3 | Last week white played, 11. Bd5, that game was played almost 2 years after this 2017 game. Perhaps, 11. Bd5, is considered as an improvement over this game? || 11. ... Nc6 | Immediately hitting at the white weak point, "The Isolated Queen's Pawn", often known as, "The Isolani". Pay careful attention as to how black increases the pressure on the white d4 pawn. || 12. a3 | White prefers to prevent black, 12. ... Nb4, rather than try to cure the problems arising from a black knight spending 2 moves to land on the d3 square. || 12. ... Bg4 | Pinning the white f3 knight reduces the white, "Defender Count", to the d4 pawn by 1. Pinned pieces are severely restricted, in this case moving the f3 knight will cost white the d1 queen. || 13. Be3 | The, "Defender Count", to the d4 pawn rises back to 2. Black to play insists that increasing the pressure on d4 is the correct plan. || 13. ... Nf5 | The, "Attack Count", on d4 rises to 3, the previously-concealed black d8 queen x-ray attack is now released. White to play must be precise here or a pawn might drop off. || 14. Qd3 | Without this not-so-obvious queen move white would be in trouble, a spread of ideas offer: (A). If 14. h3 Bxf3 15. Qxf3 Nfxd4, white must move the queen, there is no time to try, Rd1, and hope the pin brings some compensation. (B). Or if, 14. Nc3 Bxf3 15. Qxf3 Nfxd4, same story. (C). Or if, 14. d5 Ne5 15. Nbd2 Nh4, the white f3 knight is triply-attacked, white is going to receive doubled f-pawns as the black exchanges on f3 proceed. || 14. ... Nxe3 | Black elects to inflict a 3-pawn island on white, not in itself fatal, but something with which to play on in an ending. Instead, 15. ... Bxf3, does not inflict doubled f-pawns. White replies, 16. Qxf5, and amazingly black is losing a piece, the f3 bishop has no flight square. Black might continue, 16. ... Nxd4, but after, 17. Bxd4 Qxd4 18. Qxf3 Qxb2 19. Qc3 Bf6 20. Qxb2 Bxb2 21. Ra2, white has consolidated and is a piece for 2 pawns up. || 15. fxe3 | White chooses to accept the weakened kingside pawn formation, other choices seem to lose material: (A). If, 15. Qxe3 Bxf3 16. Qxf3 Nxd4 17. Qd3 Nxb3 18. Qxb3, black has an extra pawn and a bishop versus knight in a very open position. (B). Or if, 15. Qxe3 Bxf3 16. Qxf3 Nxd4 17. Qxb7 Rb8 18. Qxa7 Rxb3, black already has a piece for a pawn and white must do something about a threatened, Nc2, fork. (C). Or if, 15. Rxe3 Bxf3 16. Rxf3 Nxd4 17. Re3 Nxb3 18. Qxb3 b6, again black has an extra pawn plus a bishop versus knight in an open position. || 15. ... Bxf3 16. gxf3 Bf6 | This might look as black is obsessed with attacking the white d4 pawn. Not necessarily so, but anything which makes it more difficult for white to make use of the central / kingside pawns seems sensible. || 17. Nd2 | Perhaps played with the idea of, pawn f4 - Nf3 - Rad1 - Ne5, when black must choose which way to eliminate the well-placed white e5 knight. This might be strategically desirable, but it is black to play and ruin the proposed white plan before it starts. Instead, 17. Nc3, stops all the fun and would result in both players completing development before settling down to try and squeeze something from the imbalances in the pawn formation combined with the presence of opposite colour bishops. || 17. ... Nxd4 | An unpleasant surprise, a tactic which only works because white chose, Nd2, instead of, Nc3. The next few moves are probably forced, unless white chooses to ignore the black d4 knight, simply accepting the loss of a pawn by playing, 18. Bc2, defending the d3 queen. || 18. exd4 Bxd4+ 19. Kf1 | White begins centralising the king indicating the game continuation is going to lead to an endgame. || 19. ... Bxb2 | This capture would not be possible had white played, Nc3, closing the h8 - a1 diagonal, meaning the tactic beginning, 17. ... Nd4, would not be played. So it looks like 3 white pawns is the reward for the black piece, does it? || 20. Qxd8 | Necessary, white must accept the game goes into an ending. Instead keeping queens on with, 20. Qe3 Bxa1, gives the material imbalance trade-off of 2 black minor pieces for a white rook plus 3 pawns. || 20. ... Rfxd8 | Vacating the f8 square, the black king might also soon wish to centralise. || 21. Rad1 | Complicating backfires, instead, 21. Ra2 Rxd2 22. Rb1 Bc3, the black bishop escapes the pin, white is 3 pawns down in the sequence and reducing it to just opposite bishops will not help white. || 21. ... Bxa3 | So the tactics have netted 4 white pawns for a piece. Not only that, but white has split kingside pawns while black has 3 queenside connected passed pawns. || 22. Nc4 | White needs to get the minor pieces active, in particular ganging up on f7 might get some material back. || 22. ... Bb4 23. Rxd8+ | White cannot avoid the exchange of d-file rooks and so accepts that black is going to be given a free development tempo. || 23. ... Rxd8 24. Re4 | Setting up a tactic, the threat is, 25. Ne5, black has both the b4 bishop attacked and the f7 pawn doubly-attacked. || 24. ... Rd3 | Meeting tactic with tactic, a 6th rank skewer threatens to win more material. But black needs to be sure the back rank is not weak, providing, Bf8, can be played then a defence is available. White to play has a cute move to find which keeps the game alive, but what? Clue: Someone in the black camp is overloaded, how can white exploit this? || 25. Na5 | The white knight on a5 backwardly guards the b3 bishop with the bonus of being closer to start probing at the black queenside pawns. || 25. ... Bd6 | Avoiding a couple of blunders. (A). If, 25. ... Bxa5 26. Re8+ mate, demonstrates constant awareness of a weak back rank must be in mind when 3 kingside pawns like these remain unmoved. (B). Or if, 25. ... Rxf3+ 26. Kg2, black has the f3 rook and b4 bishop en prise without a single move available to save both. || 26. Ke2 | White protects the f3 pawn with an attack-tempo on the black d3 rook which has only a single flight square. || 26. ... Rc3 | This position has a few immediate tactics in need of careful consideration. Firstly, the white h3 pawn is under attack but the white threat of, Re8+, will be mate if the black d6 bishop strays off the a3 - f8 diagonal. Secondly, if black can play, pawn b6, the threatened white knight is in a 2-way loss - If it stands still it will be captured, if it jumps in, Nb7, saving itself, the b3 bishop falls. Thirdly, white must eliminate the active black c3 rook, such powerful pieces should not be allowed to remain. But if white offers a rook exchange then the indirect defence to the h2 pawn is not available. So how can white challenge and eliminate rooks without losing the h2 pawn? || 27. Re8+ | An important zwischenzug. If white seeks an immediate rook trade then the h2 pawn will fall to the black d6 bishop, so a tempo is spent to draw the bishop back to f8 before challenging the black c3 rook. || 27. ... Bf8 28. Re3 Rxe3+ | Declining with, 28. ... Rc1, allows white some activity, 29. Nxb7 Rh1 30. Nd8 Rxh2+ 31. Kd3 g6 32. Nxf7 Kg7 33. Ng5. While the immediate threats have passed, it is white who will find coordination against weak black pawns while all black can do is create annoyances. || 29. Kxe3 b5 | The black queenside pawn formation is in the process of becoming fixed. Instead, 29. ... b6 30. Nc6 a5 31. Ne5, white wins the black f7 pawn with plenty of piece activity to follow, though the black queenside pawns would at least still be mobile. || 30. Nc6 Bd6 | If black can eliminate the remaining white pawns then it is at least a draw, though with 4 pawns for a piece thoughts of black winning might be in mind, right? Not so simple. The black queenside pawns lack mobility, they are not threats to white but instead targets just waiting to be hit. There is also another endgame concept for both players to consider - As Hans Kmoch calls them: "The Impotent Pair". || 31. h3 | Mistakes are always just a move away. Instead, 31. Nxa7 Bc5+, black picks off the straying white knight and should have sufficient resources, 5 pawns against 2, to win an opposite colour bishop ending. || 31. ... Kf8 | Perhaps black is planning sending the king queenside to assist the pawns, either just to defend, or possibly to assist their advance? Here black might instead think about immediately throwing everything into the kingside, intending to use king activity plus pawn advances to try and wipe out the remaining white pawns. || 32. Ke4 | White gets the king off the g1 - a7 diagonal, the black a7 pawn is now safely en prise. || 32. ... a6 33. Kd5 | Perhaps not really necessary? White cannot make any gains by sending the king into the queenside. It all comes down to that, "Impotent Pair". Instead white might find gains by carrying on with the game plan a tempo ahead with the king still on e4. Having said that, there is a gain by having a king on d5, it is touching the black d6 bishop which immobilises the black c7 pawn. But is not the c7 pawn already immobilised by the white c6 knight? Yes, but white has plans of moving it, and perhaps wishes to prevent whatever activity black would have after, pawn c5. || 33. ... Ke8 | Black responds by mirroring the white strategy. Instead black might find forceful kingside pawn advances combined with king support may have forced white to reconsider the queenside plans. || 34. Bc2 An apparent tempo-gaining re-location of the bishop to a much better diagonal. || 34. ... g6 | And there is the tempo-gain, right? Not quite so simple. White could never safely snatch the black h7 pawn, examining Spassky - Fischer, Game 2, Reykjavik 1972 famously demonstrates the reason why. Essentially if next move, 35. Bxh7 g6, snares the straying white bishop, advancing with, pawn h4 - pawn h5, does not achieve freedom, the black king approaches, Kf8 - Kg7, and white loses material, almost certainly bishop plus h-pawn for 3 black pawns. So why did black not let white have the chance to self-snare the bishop? Advancing, pawn g6, is actually the start of the kingside campaign to wipe out all the white kingside pawns, or to at least inflict white with, "The Impotent Pair". || 35. Bd3 | Immobilising the black light square pawn chain, neither pawn dare move as the static pawn falls. || 35. ... Bg3 | Removing the bishop to safety permits the c7 pawn to advance, however as matters stand there is no sensible plan for it other than sitting where it is. || 36. Be2 | Explaining this Grand Master move is not easy. It does nothing wrong, fine, but why not just play the game continuation with the bishop still on the d3 square? || 36. ... h5 37. Nb8 Ke7 | The black tactic involving, pawn c6+, is an illusion as, 37. ... c6+ 38. Nxc6, saves the white knight. || 38. Nxa6 f5 39. Bxb5 g5 40. Bd3 | Giving black a difficult choice for the move to meet the time-control. || 40. ... g4 | Consistent with the plan to either eliminate all the white pawns or at least leave white with, "The Impotent Pair". Instead advancing the king would set white a somewhat tricky task of sifting out the winning idea, a few ideas run: (A). If, 40. ... Kf6 41. Nc5 g4 42. hxg4 hxg4 43. fxg4 fxg4 44. Ne4+ Kf5 45. Nxg3+ Kf4 46. Nf5 g3 47. Nh4 Ke3 48. Bf1 Kf2 49. Bg2, the white king deals with the black c7 pawn then comes back to shuffle black out of the g3 pawn, finally showing technique of mating with bishop plus knight. (B). Or if, 40. ... Kf6 41. Nc5 g4 42. hxg4 hxg4 43. fxg4 f4 44. Ne4+ Kg7 45. Ke5 f3+ 46. Kf5 Bh4 47. Kf4 f2 48. Kf3, white picks off the black f2 pawn for a winning ending. || 41. Bxf5 gxf3 | And we have white with, "The Impotent Pair", with the addition of a knight against the black bishop plus 3 pawns. Perhaps some are wondering what is this, "Impotent Pair"? Imagine a clear chess board. Add a white bishop on the f1 home square. Now place both kings on their home squares, e1 and e8. Lastly we give white a single pawn, anywhere on a home square, that is a2 across to h2, you choose. The random selection of file for the white pawn could set up any of 8 different positions. Would white be winning all these 8 different battles? No, only 7 are wins for white. "The Impotent Pair", of light square bishop plus h2 pawn will be drawn once the black king arrives on h8, the combination of 3 white attacking units cannot force the black king out of h8. Similarly, a white c1 dark square bishop plus a2 pawn cannot force promotion once the black king gets onto the a8 square. An, "Impotent Pair", of people cannot produce a new generation, these particular chess couples have the same unfortunate condition. A simple rule is if the bishop is of the opposite colour to the rook-pawn promotion square, and the defending king can get to that corner, then it is a draw. So why discuss, "The Impotent Pair", when there is a white knight still in play? We are about to find out. || 42. Nc5 | White dare not try, 42. Kc6, intending, Nxc7, allowing black, Bxc7, which would generate, "The Impotent Pair". || 42. ... f2 43. Bd3 h4 | Black fixes everything on dark squares, intending to shuffle the king for 50 moves and claim a draw on the pawn not moved combined with no captures rule. But what is the white strategy? If white dare not capture with, Nxc7, then clearly trading, Nxg3, at any point will similarly lead to a drawn, "Impotent Pair", position. However white is going to play on, so something must be available, but what? There is a remarkable attempt to win for white, the only question is can it be arranged? Perhaps take some time considering the white options before, "The Master-Plan", is revealed. And note, this is just an amazing idea, this does not automatically mean the idea either can, or will succeed. If you do not wish to receive the white strategy then search for the next appearance of the double vertical bars used to represent a closing bracket. All right, you wish to receive the strategy in advance? White must arrange a precise position, assuming black defends correctly, the following steps offer a winning method. #1. Imagine the black king is manoeuvred to h8. #2. Place the white king on the f7 square. #3. Locate the white bishop on d3. #4. Flick the knight around until it lands on g6 with check. #5. The black king must reply with, Kh7, and has walked into an x-ray attack, meaning white has, Nxh4+, creating a passed h-pawn. #6. The black king is most likely to retreat back to the h8 square. #7. Place the white king on the g6 square, vacating f7 for someone else. #8. March the h-pawn up the board as far as the h7 square. #9. Shuffle the knight to give mate on the f7 square. Note that when point #7, white placing the king on g6 occurred, the black king had an option to run queenside beginning with, Kg8, so another sub-plan emerges. #8. March the h-pawn to the h7 square. #9. Black prevents promotion by placing the bishop on the h8 - a1 diagonal. #10. White shuffles for, Nf7, and as the black king is on f8, white promotes the h-pawn forcing black to give up the bishop. #11. We assume a Grand Master can convert using bishop plus knight, though a recent experience suggests all do not have this skill. There is another point to bear in mind. Black still has f2 and c7 pawns, could these influence the white idea? This question will be answered as the game proceeds. Lastly, remember the first line of, "The Master-Plan"? #1. Imagine the black king is manoeuvred to h8. This is easier said then done, and perhaps we must ask the question, can it actually be done? || 44. Ne4 Kf7 45. Ng5+ Kf6 46. Nf3 | White has manoeuvred to create a containment field, this, "Mini-Barrier", is the control of the, e5, f5, g5, squares all in a line, though the, e6, g6, squares are also claimed. The idea is to restrict the black king in such a way it retreats and the white king can advance. Once the white king makes progress, then shuffling the white knight and bishop will create many more different, "Mini-Barriers", with the ultimate aim of achieving the position described in, "The Master-Plan". A certain feature of the, "Mini-Barrier", should be noted. The barrier requires the bishop and knight to sit on the same shade of square, here it will be the light squares. The white king is also going to move on the light squares for virtually all the game, there will of course be the odd exceptions. Yes, this means the mobility of the white bishop will be slightly restricted by friendly units. But this is what is absolutely necessary for the knight to contribute and because black has a dark square bishop it is the simplest way for the white king to join the chase. || 46. ... Ke7 47. Bc4 Kf6 48. Ke4 | The white king is trying to infiltrate on the kingside, the focal point of this short-term fight will be the f5 square. As it stands the black king can shuffle while continually touching the f5 square, so white must claim these black shuffle-squares. This is a 3-stage process. #1. Stop imagining pieces moving around to create the required, "Mini-Barrier", but instead mentally place letter, "X", on each square to be denied the black king. #2. Then work out on which squares the white pieces must stand to take control of those squares marked with, "X". #3. Lastly find the moves to get the pieces from their present position to those required for the new, "Mini-Barrier". || 48. ... Kg6 | Keeping a touch on the f5 square. || 49. Nd4 Kf6 50. Nc6 Kg5 51. Ne7 Kf6 52. Nd5+ | Taking control of the e7 and f6 squares. || 52. ... Kg6 53. Bd3 | Placing an x-ray attack on the f5 and g6 squares. A feature of, "Mini-Barriers, is the pattern of the controlling pieces being on the same rank or file separated by a single square. Here they are on d3 and d5, previously they were on d3 and f3. Another useful formation to remember is with the pieces touching each other on a diagonal. Imagine a bishop on c3 and a knight on b2, these pieces are touching each other on the a1 - h8 diagonal. They have created an impenetrable, "Mini-Barrier", the squares, a4, b4, c4, d4, d3, d2, d1, all marked with letter, "X", denying the black king access to those squares contained within the force-field. Perhaps this formation could be described as a, "Short-Shaft Arrow", with the arrow head being the denied squares. || 53. ... Kg5 54. Kf3 | The, "Mini-Barrier", is now the, f4, f5, f6, g4, g6, squares. || 54. ... Kh5 | Keeping the white king off the g4 square. || 55. Nf6+ Kg5 56. Ne4+ | A very useful square. If the black king plays either, Kf5, or, Kg6, he has walked into an x-ray attack, white will have, Nxg3+, winning the black g3 bishop. || 56. ... Kh5 | White to play must now call on a technique more often seen in king and pawn endings. Clue: White must have the exact position as appears on the board now, but with black to move. || 57. Ke2 | A couple of the white units were in a form of self-zugzwang. If the e4 knight moves then control of the g5 square is lost. If the d3 bishop moves off the b1 - h7 diagonal then the x-ray attack on the g6 square is lost. If the white bishop moves off the f1 - a6 diagonal then black promotes the f2 pawn with check. So the only unit capable of movement is the white king, he intends returning to the f3 square when the black king sits on the h5 square. || 57. ... Kh6 58. Ke3 | Returning immediately to f3 will not alter the sequence of mutual king retreats and advances. White is in the process of, "Triangulating", that is spending 3 moves to return home, joining imaginary dots in the centre of each square creates a triangle. || 58. ... Kg7 | Black accepts the white king can gain an entry and so prefers to retreat rather than be forced. Instead, 58. ... Kh5 59. Kf3 Kh6 60. Kg4 Kg7, and the white king can choose whichever 5th rank square takes his fancy. || 59. Kf3 Kf7 60. Bc4+ | "Mini-Barrier", is the, d6, e6, f6, f7, g8, squares. This loses control of the g6 square, but just retreating, Bd3, regains the previous restrictive formation if required. || 60. ... Kg6 61. Kg4 c6 | Black chooses not to retreat the king which would allow the white king to advance at least as far as f6 or g6, depending on where black places the king. However on c6 this pawn might become a target, back on c7 it was defended by the g3 bishop. || 62. Bd3 Kf7 63. Kf5 Ke7 | Black chooses to centralise the king rather than slowly be shuffled onto the h-file while the white king gets closer to the f7 square. || 64. Bc4 | "Mini-Barrier", of, d6, e6, f6, g6, f7, g8, squares, means that any black king move allows the white king to hit the 6th rank. Black to play is now going to surprise many a kibitzer. || 64. ... f1=Q+ | Black does not wish to retreat the king and so gives away the f2 pawn in order to give the g3 bishop the f2 and e1 squares for shuffle moves. Fine, but this now means the white bishop is no longer tied down to preventing promotion, it is free to move to any diagonal rather than remain on the f1 - a6 diagonal. || 65. Bxf1 Be1 66. Be2 Kf7 67. Bd1 Ke7 68. Ba4 | White is about to win the black c6 pawn, after which the 3 white attack units can focus entirely on trying to push the black king onto the h8 square. || 68. ... Bb4 69. Kg4 | Dragging the black bishop back onto the e1 - h4 diagonal, perhaps not wishing it to defend the h4 pawn from the d8 - h4 diagonal. || 69. ... Be1 70. Bxc6 | White now has to either force mate or capture the black h4 pawn by move 120 at the latest or black can claim a draw by the 50-move rule. If black needed to give away the c7 and f2 pawns, then perhaps this should have been done at the earliest opportunity, meaning had white tried to infiltrate the kingside as in the game, then quite a few moves would already be on the 50-move count. || 70. ... Ke6 | There are similarities between a bishop plus knight against a bare king, these will appear as, "Mini-Barriers", are set up then dismantled to set up another. However there is a massive difference, the presence of a black dark square bishop means white can never make full use of the dark squares, as is required in the cross-board sweep from unfavourable corner to favourable corner. square. So aiming for a mate on the a8 square is not on, it must be, "The Master-Plan", as previously explained, and done before or on move 120. || 71. Ng5+ Kf6 72. Nf3 Bg3 73. Bd5 | "Mini-Barrier", on, e5, f5, g5, h5, e6, f7, g8, squares. Note how the white knight and king can also set up the, "Short-Shaft Arrow", formation, permitting the bishop to control other squares from the centre. It is however now the turn of the white king to wander around while the bishop and knight play for containment. || 73. ... Bf2 74. Kf4 | White assesses the king action on the kingside will not give success, so transfer queenside and try pushing along the 7th rank. || 74. ... Bg3+ 75. Ke4 Bf2 76. Bb7 | An important re-arrangement. If the white king is going queenside to challenge along the 7th rank, then the white bishop is needed to create some, "Mini-Barriers", on the kingside, the obvious square is where the white king has recently vacated. || 76. ... Bg3 77. Bc8 Bf2 78. Bg4 | "Mini-Barrier", established on, e5, f5, g5, h5, squares. || 78. ... Bg3 79. Kd5 Bf2 | White needs another, "Mini-Barrier", shuffle to push the black king back a little. || 80. Nd2 | Retreating in order to advance, though the precise target square is not so obvious. As the white king and knight re-shuffle themselves, a thought of could the black king make a run into the centre must have been going through the minds of both players. Of course the black king is not going to be so stupid as to march to a1 and sit there. In that case white would gang up on the black h4 pawn with king and knight, and the resulting ending would be a win for white, the black king being unable to occupy the h8 promotion square. However if the black king can keep within retreating-distance of h8, then wandering as far as e5 or f4 might do no harm, and would frustrate the white, "Master-Plan". Perhaps time is now a critical factor, move 80 suggests either player could be close to only having 30 seconds increment per move. || 80. ... Bg3 | The king infiltration plan for black fails, instead, 80. ... Kg5 81. Ne4+, wins the loose black f2 bishop. || 81. Kc6 | Trying to out-flank the black king who now has a big decision to make with whatever time is available. || 81. ... Ke7 | The black king chooses to prevent the white king getting in behind him. Instead, 81. ... Ke5, with the idea of drifting around the e5, d4, e4, f4, squares as allowed, might have given white problems in setting up, "Mini-Barriers", and in which direction should the white forces then try to push the black king? Not only that, but with each new white formation the white move-count gets closer and closer to that magic 120 when black can claim a draw, assuming the necessary conditions are satisfied. || 82. Nc4 | The knight on d2 has many routes to the target square. || 82. ... Bh2 83. Nb6 Bg3 84. Nd5+ | This is the furthest apart the white minor pieces have been in their latest, "Mini-Barrier", of, f5, f6, e6, d6, d7, squares. For exercise only, think of swapping the white king and knight around, then the, "Mini-Barrier", would be, f5, e6, d6, e7, d7, d8, c8, the black king would be denied a route to the b8 square, should that be important to white. || 84. ... Kd8 | White needs more, "Mini-Barriers", on the kingside, all designed to push the black king closer to the h8 corner, and as the black king retreats the white king advances. || 85. Ne3 Ke7 | On e7 the black king guards the d6 square, this releases the g3 bishop for shuffle-duty between the g3 and e1 squares. || 86. Nf5+ | Forcing the black king to decide, go for d8 or drift toward the h-file. || 86. ... Kf6 | Again, how much thinking time available to the players is not known. "Armchair Analysts", have all the advantages, knowledge of how the game went plus plenty of relaxing non-competitive time to study other options. Heading queenside with the black king looks interesting and probably easier to handle, no fear of unnecessarily blundering into a surprise mating net or sneak-combination. So how could white proceed if the black king tried to find shelter on the queenside? White would have to gang up on the black h4 pawn with king and knight, capture, Nxh4, black exchanges with, Bxh4, then it is a question of which king achieves their aim concerning the promotion h8 square. So perhaps this sample line gives the answer?: If, 86. ... Kd8 87. Kd5 Be1 88. Ke6 Bf2 89. Kf6 Be1 90. Kg5 Ke8 91. Nxh4 Bxh4 92. Kxh4 Kf8 93. Kg5 Kg7, black gets a draw. But that above line fails to appreciate the value of, "Mini-Barriers", the white g4 bishop failed to contribute, can it assist from the queenside?: If, 86. ... Kd8 87. Bd1 Be1 88. Ba4, "Mini-Barrier", will be, c6, d6, d7, e7, e8, squares, 88. ... Bf2 89. Kd5 Be1 90. Ke6 Bf2 91. Kf6 Be1 92. Kg5 Bf2 93. Nxh4 Bxh4 94. Kxh4 Ke7 95. Kg5 Kf8 96. Kg6 Kg8, the black king gets to h8 for the draw. So it seems the white king plus knight ganging up on the black h4 pawn is too slow, as soon as the knight loses control of the e7 square the black king skulking on d8 sprints in. So the black king need only sit on d8 and white must find a variety of, "Mini-Barriers", to force him kingside, all this to be achieved at the latest by white move 120. But in the game black is taking the king kingside... || 87. Kd7 Be1 88. Ne3 | Re-grouping, the black king must be kicked off the f6 square. || 88. ... Bg3 89. Be6 | Vacating the g4 square while controlling the f7 square. || 89. ... Be1 90. Ng4+ | Perhaps giving the black king a tricky decision to make? || 90. ... Kg7 | The black king volunteers to retreat to the g7 square, could there be an alternative in, 90. ... Kg5, forcing white to spend moves to get him onto the g7 square? Take care, there is a danger in having the black king on g5, place white king on g7, bishop on g4, then play, Ne6+ mate! Of course, the white king will never settle on g7, the black bishop will disrupt the mating-pattern with a timely check on the a1 - h8 diagonal. So how about, 90. ... Kg5 91. Ke7 Bg3 92. Kf7 Be1 93. Ne5 Bg3 94. Nf3+ Kh5 95. Bg4+ Kh6 96. Kf6 Bf2 97. Kf5 Bg3 98. Ng5 Be1 99. Nf7+ Kg7, success, but how does white re-group, in particular centralising the king, while preventing the black king using h6 to get back to the g5 square? || 91. Bf5 | "Mini-Barrier", e6, f6, g6, h6. || 91. ... Bg3 | Surely black, 91. ... Kf7, would make white spend a few more moves in order to get the white king onto the e6 square? Something like, 91. ... Kf7 92. Bd3 Bg3 93. Bc4+ Kg6 94. Ke6 Be1 95. Bd3+ Kg7, with a position roughly similar to game. || 92. Ke6 | Denying the black king the f6 and f7 squares, someone needs to hit the black king on g7, expect another re-grouping. || 92. ... Be1 93. Bc2 | Vacating the f5 square preparing, Nf5+. || 93. ... Bc3 | Perhaps denying the white king the e7 square, but does he actually need it? || 94. Ne3 Be1 95. Nf5+ | A wonderful square for the knight, it backwardly hits the black h4 pawn while controlling the h6 and g7 squares. || 95. ... Kg8 | Trying to keep the white king off the f7 square, but white has a neat trick in mind on how to scare the black king out of guarding this vital white entry point. || 96. Bb3 | Creating an x-ray attack on the black g8 king, it is about to be pushed off the g8 square. || 96. ... Kh7 | Again black could force an extra move out of white with, 96. ... Bg3 97. Ke7+, a rarity, a king moves gives check, 97. ... Kh7 98. Kf7, which would be the game position with an extra move on the scoresheet. || 97. Kf7 Bf2 98. Bc2 | Another x-ray attack, this dare not be ignored. || 98. ... Kh8 | Instead, 98. ... Be1 99. Nxh4+, black drops the h4 pawn to a discovered check, the passed h3 pawn can join the attack which will be decisive. || 99. Ne7 | Now that the black king is totally immobilised by the white f7 king and c2 bishop, the white knight shuffles for a monster-check on the g6 square. || 99. ... Bg3 100. Ng6+ Kh7 | The black king has been forced to walk into an x-ray attack. || 101. Nxh4+ | The white, "Master-Plan", envisaged way back after black move 43 has come to pass. Whether all these white manoeuvres were always going to succeed is another matter. The fact is that it has worked, let Fritz and friends argue over other defensive options black could have tried. || 101. ... Kh8 | Advancing with, 101. ... Kh6, seems not to help black, a few ideas run: (A). If, 101. ... Kh6 102. Nf5+ Kh5 103. Nxg3+ Kh4 104. Nf5+ Kxh3, and white settles down to approximately 35 moves to give mate with bishop plus knight. (B). Or if, 101. ... Kh6 102. Nf5+ Kh5 103. Nxg3+ Kh4 104. Bf5 Kxg3 105. Kg6 Kh4 106. Kh6 Kg3 107. Kg5, and the white h3 pawn has a free run to the h8 promotion square. (C). Or if, 101. ... Kh6 102. Nf5+ Kh5 103. Nxg3+ Kh4 104. Bf5 Kxg3 105. Kg6 Kf4 106. h4 Ke5 107. h5 Kd6 108. Kg7, and again the white pawn gets through to the h8 square. || 102. Nf5 Bf2 103. Kg6 Black resigns, 1-0 | The white king is ready to support the advance of the white h-pawn all the way to the h7 square. Of course, when white plays, pawn h4, black has, Bxh4, but white, Nxh4, leaves white a bishop plus knight up, should be a simple finish for a Grand Master. So assume white gets a pawn onto the h7 square with the black king on h8, occupying the promotion square. All white need do then is manoeuvre for, Nf7+ mate. Instead the black king might vacate the h-file, perhaps settling on f8, and then place the bishop on the a1 - h8 diagonal. Again white advances, pawn h7, lands the knight on the f7 square, then simply, h8=Q, black captures, Bxh8, and finally white, Nxh8, leaving white those 2 minor pieces to give that 35 or so moves mate. || * * * ## Unannotated Game. White: V. Kotronias, 2524. Black: S. Estremera, 2339. Event: Rilton Cup (Stockholm) 2017-18. Opening: Petroff Defence, Classical Attack, C42. 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bf5 7. O-O Be7 8. c4 dxc4 9. Bxc4 O-O 10. Re1 Nd6 11. Bb3 Nc6 12. a3 Bg4 13. Be3 Nf5 14. Qd3 Nxe3 15. fxe3 Bxf3 16. gxf3 Bf6 17. Nd2 Nxd4 18. exd4 Bxd4+ 19. Kf1 Bxb2 20. Qxd8 Rfxd8 21. Rad1 Bxa3 22. Nc4 Bb4 23. Rxd8+ Rxd8 24. Re4 Rd3 25. Na5 Bd6 26. Ke2 Rc3 27. Re8+ Bf8 28. Re3 Rxe3+ 29. Kxe3 b5 30. Nc6 Bd6 31. h3 Kf8 32. Ke4 a6 33. Kd5 Ke8 34. Bc2 g6 35. Bd3 Bg3 36. Be2 h5 37. Nb8 Ke7 38. Nxa6 f5 39. Bxb5 g5 40. Bd3 g4 41. Bxf5 gxf3 42. Nc5 f2 43. Bd3 h4 44. Ne4 Kf7 45. Ng5+ Kf6 46. Nf3 Ke7 47. Bc4 Kf6 48. Ke4 Kg6 49. Nd4 Kf6 50. Nc6 Kg5 51. Ne7 Kf6 52. Nd5+ Kg6 53. Bd3 Kg5 54. Kf3 Kh5 55. Nf6+ Kg5 56. Ne4+ Kh5 57. Ke2 Kh6 58. Ke3 Kg7 59. Kf3 Kf7 60. Bc4+ Kg6 61. Kg4 c6 62. Bd3 Kf7 63. Kf5 Ke7 64. Bc4 f1=Q+ 65. Bxf1 Be1 66. Be2 Kf7 67. Bd1 Ke7 68. Ba4 Bb4 69. Kg4 Be1 70. Bxc6 Ke6 71. Ng5+ Kf6 72. Nf3 Bg3 73. Bd5 Bf2 74. Kf4 Bg3+ 75. Ke4 Bf2 76. Bb7 Bg3 77. Bc8 Bf2 78. Bg4 Bg3 79. Kd5 Bf2 80. Nd2 Bg3 81. Kc6 Ke7 82. Nc4 Bh2 83. Nb6 Bg3 84. Nd5+ Kd8 85. Ne3 Ke7 86. Nf5+ Kf6 87. Kd7 Be1 88. Ne3 Bg3 89. Be6 Be1 90. Ng4+ Kg7 91. Bf5 Bg3 92. Ke6 Be1 93. Bc2 Bc3 94. Ne3 Be1 95. Nf5+ Kg8 96. Bb3 Kh7 97. Kf7 Bf2 98. Bc2 Kh8 99. Ne7 Bg3 100. Ng6+ Kh7 101. Nxh4+ Kh8 102. Nf5 Bf2 103. Kg6 Black resigns, 1-0 * * * ## Repeat annotations from 16 February 2020 coaching session up to white move 11. 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 | All players of the Petroff will of course have a line ready against, 4. Nxf7, the Cochrane Gambit. Is this bold strike sound? Not really, but it does have a tremendous plus score in the limited database referenced for these sessions. Here is a sample of the joys / horrors which can happen. S. Sulskis (2545) - T. Michalczak (2369), 6th European Individual (Warsaw) 2005, went: 4. Nxf7 Kxf7 5. d4 c5 6. Bc4+ d5 7. exd5 Bd6 8. O-O cxd4 9. Qxd4 Bf5 10. Bf4 Re8 11. Nc3 a6 12. Rae1 Rxe1 13. Rxe1 Qc7 14. Bxd6 Qxd6 15. Re5 Bxc2 16. Re6 Qd8 17. d6 Kf8 18. Nd5 Nc6 19. Qf4 Bg6 20. Nxf6 gxf6 21. Qh6+ 1-0. Cute, the light squares are toxic, that c4 bishop x-ray attack leads to fatal double checks: (A). If, 21. ... Kg8 22. Re8+ mate. (B). Or if, 21. ... Kf7 22. Re7+ mate. As stated above, players of the Petroff Defence should be prepared for the Cochrane Gambitt. The 65% white wins suggests some have not done their homework. || 4. ... Nxe4 5. d4 d5 6. Bd3 Bf5 | Up until here the game has been following, "Mainline Moves", that is the most popular choice has been repeated. But here black has deviated into an uncommon sideline, or to be more accurate, black has specifically prepared this variation for this opponent. Far more popular is, 6. ... Nc6, then comes, 6. ... Be7, 6. ... Bd6, and less popular than the game choice comes, 6. ... Bg4, 6. ... Nd6, 6. ... Nf6. The spread of choices tells us that the top players cannot agree on the best approach for black. So what should the club player do? Pick a line which visually appeals, study it, noting which piece exchanges are sought, which piece exchanges are avoided, which pawns move and which pawns stay at home until forced to move. In this way a general feeling of how to handle the variation should emerge, the only problem is to sort out over the board in which order to make the moves to arrive at the middlegame. Perhaps inspiration from a group of like-thinking minds might assist? City of Budapest - Paris Chess Club, Correspondence 1842, posted this imbalanced encounter: 6. Bd3 Bd6 7. O-O O-O 8. c4 Be6 9. Qc2 f5 10. Qb3 dxc4 11. Qxb7 c6 12. Bxe4 fxe4 13. Ng5 Bf5 14. Nc3 Qd7 15. Qxd7 Nxd7 16. Ngxe4 Bc7 17. Re1 Rab8 18. Re2 Nb6 19. Nc5 Bd6 20. N5e4 Bc7 21. Nc5 Bd3 22. Re3 Bc2 23. Ne6 Rf7 24. Nxc7 Rxc7 25. Re2 Bd3 26. Bf4 Bxe2 27. Bxc7 Re8 28. Bxb6 axb6 29. Re1 Bh5 30. Rxe8+ Bxe8 31. Ne4 b5 32. a3 Bg6 33. f3 Kf7 34. Kf2 Ke6 35. Ke3 h6 36. g4 Kd5 37. Nc3+ Kd6 38. f4 Be8 39. f5 Bd7 40. Ne4+ Ke7 41. Kf4 Be8 42. Ke5 Bf7 43. h4 Bd5 44. g5 hxg5 45. hxg5 Bg8 46. g6 1-0. || 7. O-O Be7 8. c4 | A dynamic approach, white is willing to accept the, "Isolated Queen Pawn", and play around it with the pieces. Instead, 8. Re1 Nc6 9. Nc3, is a different way to start challenging the black central control. || 8. ... dxc4 9. Bxc4 O-O 10. Re1 | With now only a handful of games on the database it is not possible to judge, 10. Nc3, as better or worse. || 10. ... Nd6 | This is a key-move in the system beginning with black, 6. ... Bf5, on d6 this knight assists the defences of some light squares, in particular the f7 pawn. || 11. Bd5 | According to limited database this is a new move. Instead, 11. Bd3, led to a draw in 18 moves, meaning this bishop retreat was not seriously tested, However, 11. Bb3, still probing the black f7 pawn gave a lively early middlegame followed by a most fascinating endgame. So what is the point of centralising the white bishop on d5? Perhaps white was not completely prepared for the variation of black, 6. ... Bf5, and is selecting a move which no respecting chess engine would crunch through. In essence, if black had a new idea ready to spring on white, then perhaps this strange but safe shuffle is neutralising any dangerous preparation, both players must start thinking independently. || * * *