22 February 2024

Video completed: The 4...Nf6 Caro-Kann by Nigel Davies


I recently completed the FritzTrainer The 4...Nf6 Caro-Kann by GM Nigel Davies, which was published in 2016. It covers lines in both the Bronstein-Larsen (5...gxf6) and Tartakower (5...exf6) variations for Black, which is unusual, since Caro-Kann opening resources normally focus on one or the other, because of their major structural differences. The content description is copied below; there are also 16 quiz positions at the end, mostly from the Bronstein-Larsen side. In each of the lines, a full game is presented as the baseline, although certain sub-variations or ideas are demonstrated within it. There is also a separate, larger database of model games included in both variations.

As is reflected in my annotated games database attached to this blog, I've long played the Classical (4...Bf5) variation of the main line Caro-Kann. I have no intention of giving it up, but the 4...Nf6 variations are of interest both from a general improvement standpoint and for potentially expanding my personal repertoire. The position-types that result have some resemblance to familiar ones, but especially the Bronstein-Larsen requires a more dynamic, attacking approach from Black. The positional imbalances that result are also a useful way to deliberately (if more riskily) play for a win as Black, versus the normally more staid positions of the Classical variation.

Although this video set is one of the more comprehensive ones available on the topic, it still covers a lot of territory without much depth, particularly in the main line Bronstein-Larsen 6. c3, where Davies recommends ...h5 as Black's response, rather than the much more common ...Bf5. The database supports this choice, however, with ...h5 scoring significantly better. White has a large number of 6th move possibilities, as can be seen below, so this lack of depth is probably unavoidable.

I avoided the Tartakower variation when originally building my personal repertoire largely because of Korchnoi's defeat against Karpov in the world championship series while relying on it. That said, it's certainly solid and in fact underwent something of a renaissance several years after this video was published. I don't believe it's quite as trendy at the moment, but there are many current games with it and it scores significantly better than the Bronstein-Larsen, so it may be worth delving into further. If you are looking for an introduction to the modern (2017 and on) treatment of the Tartakower, this blog post by GM Max Illingworth on Chess.com may be of interest: https://www.chess.com/blog/Illingworth/the-modern-caro-kann-antidote-to-3-nc3

  • The 4...Nf6 Caro-Kann: 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6
  • 01: Introduction [06:28]
  • 02: 5.Nxf6 gxf6 Strategy 1 - Kavalek,L - Larsen,B [11:17]
  • 03: 5.Nxf6 gxf6 Strategy 2 - Victor Ciocaltea - Mikhail Botvinnik [10:09]
  • 04: 5.Nxf6 exf6 Strategy 1 - Rosino,A - Bilek,I [14:29]
  • 05: 5.Nxf6 exf6 Strategy 2 - Torre,E - Kortschnoj,V [12:00]
  • 06: 5.Nxf6 exf6 Strategy 3 - Tarrasch,S - Tartakower,S [07:56]
  • 07: 5.Nxf6 exf6 Strategy 4 - Perez - Alekhine,A [07:52]
  • 08: 5.Nxf6 gxf6 6.c3 Bf5 - John Fedorowicz - Nigel Rodney Davies [09:47]
  • 09: 5.Nxf6 gxf6 6.c3 h5 - Eggleston,D - Short,N [15:40]
  • 10: 5.Nxf6 gxf6 6.Nf3 Bg4 7.Be2 Qc7 8.Be3 - Tiviakov,S - Short,N [06:42]
  • 11: 5.Nxf6 gxf6 6.Nf3 Bg4 7.Be2 Qc7 8.0-0 - Lombaers,P - Jones,G [06:46]
  • 12: 5.Nxf6 gxf6 6.g3 h5 - Nakar,E - Paichadze,L [10:29]
  • 13: 5.Nxf6 gxf6 6.Bc4 Bf5 7.Ne2 Nd7 8.Ng3 Bg6 9.0-0 - Aseev,K - Bronstein,D [05:17]
  • 14: 5.Nxf6 gxf6 6.Bc4 Bf5 7.c3 e6 8.Ne2 - Pohla,H - Bronstein,D [06:09]
  • 15: 5.Nxf6 gxf6 6.Bc4 Bf5 7.c3 e6 8.Qf3 - Ivanovic,B - Bronstein,D [08:58]
  • 16: 5.Nxf6 gxf6 6.Bf4 - Davies,N - Groszpeter,A [04:45]
  • 17: 5.Nxf6 gxf6 6.Be3 - Bakulin,N - Bronstein,D [08:53]
  • 18: 5.Nxf6 gxf6 6.Ne2 - Kopaev,N - Bronstein,D [07:35]
  • 19: 5.Nxf6 gxf6 6.Qd3 - Barczay,L - Bronstein,D [05:32]
  • 20: 5.Nxf6 exf6 6.c3 Bd6 7.Bd3 0-0 8.Qc2 Re8+ 9.Ne2 Kh8 White castles short - Tiviakov,S - Spraggett,K [10:37]
  • 21: 5.Nxf6 exf6 6.c3 Bd6 7.Bd3 0-0 8.Ne2 Re8 9.Qc2 Kh8 White castles long - Fontaine,R - Asrian,K [07:19]
  • 22: 5.Nxf6 exf6 6.c3 Bd6 7.Bd3 Be6 - Arakhamia-Grant,K - Korchnoi,V [07:33]
  • 23: 5.Nxf6 exf6 6.Bc4 Qe7 7.Qe2 Be6 8.Bxe6 - Ivanovic,B - Miladinovic,I [09:03]
  • 24: 5.Nxf6 exf6 6.Bc4 Qe7 7.Qe2 Be6 8.Bb3 - Estevez,G - Lechtynsky,J [09:43]
  • 25: 5.Nxf6 exf6 6.Bc4 Qe7 7.Be2 - Karjakin,S - Jobava,B [11:19]
  • 26: 5.Nxf6 exf6 6.Bc4 Bd6 - Bednarski,J - Donner,J [11:38]
  • 27: 5.Ng3 g6 - Sax,G - Larsen,B [16:23]
  • 28: 5.Ng3 h5 - Elezi,E - Akopian,V [09:21]

19 February 2024

The learning cycle articulated

In Annotated Game #267 ("How openings are really learned") I highlighted the cycle for acquiring deeper understanding of openings and their early middlegame plans: play consistently, analyze your games, and you will inevitably expand your understanding of them step by step.

Separate but closely related to that, I recently ran across what I thought was a well-articulated (and simple) version of the broader learning cycle at Chessmood:


The full article addresses other things like the importance of mindset, but below is how they present the cycle. It's worth clarifying that the "Practice" step, in the sense we are talking about, does not mean reviewing your stored opening repertoire (or other knowledge) by yourself; rather, it is about using your chess knowledge (opening, middlegame, endgame) under actual combat conditions. Improvement via analyzing your own games then becomes an iterative process that yields concrete results over time, even if temporary setbacks occur.


The chess improvement formula

It’s quite simple.
Study -> Practice -> Fix -> (Repeat)

You learn something first.
You practice it; otherwise, you’ll forget it.
You fix the mistakes you make.
Then you learn new things, and the cycle continues.

Annotated Game #267: How openings are really learned

This final-round game illustrates several useful themes, including recent ones highlighted like the importance of playing an idea at the right time and the power (and necessity) of simple development. The mutual "??" moment on move 32 shows how time trouble was affecting my game, as I had a chance to turn things around, and played the correct move one tempo too late. 

This game is also a perfect example of a broader theme of how openings really get learned - namely, the hard way.

During the game it was clear that my opponent as White was out of his personal experience in the opening phase of a Panov variation of the Caro-Kann. This however did not stop him from finding the correct attacking setup and plan, which to be honest is not that hard for an experienced White player. In contrast, never having faced/studied the position starting on move 11, I struggled to adapt and ended up committing the sin of moving a piece multiple times in the opening to no good effect, which essentially handed my opponent the initiative and an excellent attack.

I did not feel too badly about missing the one tactic, since my opponent had simply outplayed me for most of the game, although it stung a bit. The main lesson for me was the need to keep playing consistently, analyze my games, and constantly expand my understanding of openings and early middlegame plans in that manner. Databases and references are great, but understanding comes from the actual fight on the board.

[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "Class A"] [Black "ChessAdmin"] [Result "1-0"] [ECO "B14"] [Annotator "ChessAdmin/Stockfish 16"] [PlyCount "73"] 1. c4 c6 2. e4 d5 3. exd5 cxd5 4. d4 {the Panov variation, by transposition.} Nf6 5. Nc3 e6 6. Nf3 Be7 {my opponent did not seem particularly familiar with the opening, or at least this variation, based on the amount of time he took at the board. However, he found a good path as White - perhaps not to difficult to do.} 7. cxd5 Nxd5 8. Bd3 Nc6 9. O-O O-O 10. Re1 Nf6 11. Bg5 {I was only familiar with the a3 line, so now had to start thinking about the differences.} h6 {logical and objectively best.} (11... Nb4 {would be the direct way to take advantage of White's failure to guard the b4 square.} 12. Bb1 {the bishop is fine on this square, but the drawback for White is locking the rook on the a-file.}) 12. Bh4 a6 $6 {this turns out to be too slow.} (12... Nh5 {immediately trades off a minor piece, reducing White's attacking prospects.}) (12... Bd7 {simple development is also good, while clearing the c8 square for a rook.}) 13. Rc1 Nb4 $6 {this is now possible, but is only a distraction for Black, as the light-square bishop is just fine on b1. This would have made more sense played earlier, as shown on move 11.} 14. Bb1 Nbd5 $6 {compounding my loss of time in the opening. White will now get an attack rolling without my pieces being well-enough developed to counter it.} (14... Bd7 $16 {would be at least somewhat better, also allowing the bishop to go to e8 on defense.}) 15. Qc2 $16 Nb4 16. Qd2 Nbd5 17. Ne5 {I thought for a long time here and could not find a good response. I thought the text move would hold, but White is able to bring too many pieces into the attack.} Ne8 (17... Ne4 {is the engine's best try.} 18. Qc2 Bxh4 19. Qxe4 f5 20. Qf3 $16) 18. Nxd5 Bxh4 19. Qd3 f5 {this was basically as far as I originally saw in calculating the sequence on move 17.} 20. Nf4 $1 $18 {now, however, the knights are dominant.} Bg5 21. Neg6 Bxf4 22. Nxf4 Qd6 23. Qe3 Nc7 24. a3 {restricting the Black queen's activity by controlling b4.} Nd5 25. Nxd5 Qxd5 26. Rc5 {I missed this, which ends up giving White too much pressure on e6 by driving away the queen.} Qd8 27. Ba2 {the game is essentially over at this point, but I play on in hopes of a blunder from my opponent.} Kh8 28. Qe5 Bd7 {far too late for this basic developing move.} 29. Rc7 {well played by my opponent, as Black has no good response.} Rc8 30. Rxb7 Rf6 31. d5 Rg6 {setting up some desperation tactics involving the g-file. This was the correct practical choice, especially under mutual time pressure.} 32. dxe6 $4 (32. Qd6) 32... Qg5 $4 {the wrong choice of threat to make, in time pressure.} (32... Bc6 $1 {forking g2 and the Rb7 wins. I saw this earlier as a possibility, but somehow hallucinated that White had an effective comeback that negated the threat.} 33. g3 Bxb7 $19) 33. g3 $18 Bc6 {too late.} 34. Rb8 Rxb8 35. Qxb8+ Kh7 36. e7 Qh5 37. Qg8# {I had not seen this, with the Ba2 now covering g8.} 1-0

18 February 2024

Annotated Game #266: The importance of playing an idea at the right time

I happened to get two Whites in a row and I was not unhappy, given the previous result, that this game paralleled Annotated Game #265's Symmetrical English until move 8. Black's asymmetric reaction in the center with ...e5 created an imbalance in the position which I could have reacted to with the idea of Bg5, looking to trade the now "bad" bishop off. However, I pass up several early opportunities, only to play it at a much worse time later in the game, which nearly gets the bishop trapped. A similar theme applies to my light-square bishop's back-and-forth maneuvers.

The game overall was more stressful than the previous one, with Black's space advantage and better piece activity keeping me on the ropes for much of the time, although I had a number of chances to equalize (and did so several times). Time trouble for both sides played a major role in the outcome, as well.

[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "ChessAdmin"] [Black "Class A"] [Result "1/2-1/2"] [ECO "A37"] [Annotator "ChessAdmin/Stockfish 16"] [PlyCount "99"] 1. c4 c5 2. Nf3 Nc6 3. Nc3 g6 4. g3 Nf6 5. Bg2 Bg7 6. O-O O-O 7. d3 d6 8. Rb1 e5 {first break in the symmetry. Black opts to seize territory in the center, at the cost of obstructing the Bg7.} 9. a3 {continuing with the plan of the b-pawn advance.} a5 10. Ne1 (10. Bg5 $5 {is an interesting idea, now that there is an obstructing pawn on e5. Normally the bishop is needed on d2 (or perhaps b2) to help counter the Bg7's pressure.} h6 11. Bxf6 {exchanging the "bad" bishop for Black's good knight.} Bxf6 12. Ne1) 10... Be6 11. Nc2 {it would be better to develop the bishop.} (11. Bg5 {fights for d5 indirectly as well.}) 11... d5 {now Black's central play equalizes.} 12. cxd5 {at the time, I thought there was no other real option. However, the Bg5 idea is still good.} Nxd5 13. Ne3 (13. Ne4 $5) 13... Nde7 14. Bd2 {finally developing the piece. Black has a space advantage by this point, so I have to look for ways to give my pieces greater scope.} Rb8 15. Nb5 {played after long thought. I felt this had better long-term prospects than alternatives such as Na4. I did not consider Ne4 here, having dismissed it earlier.} Qb6 {first move out of the database. I didn't think the queen was well-placed on b6. However, it does provoke my next move, which helps resolve the situation on the queenside for Black.} 16. a4 {this gives up the idea of the b4 break, but I didn't think it was happening anyway by this point in the game. I thought it was a solid option to maintain the knight outpost.} (16. Qa4 $5 {would be one way to develop the queen and free up space for other pieces. White can then chase away the black queen with Nc4.}) 16... Qd8 $15 17. Nc4 {pressuring a5 and controlling d6. Black according to the engine still has a small advantage, but at least I was now striking back in his territory.} b6 18. b3 (18. f4 $5 {is an interesting alternative, preferred by the engines. In the game, I considered it for a while and ultimately did not like due to the opening of the g1-a7 diagonal, which I thought would be better for Black.}) 18... Bd5 19. Bh3 $11 {choosing to preserve the bishop. My opponent seemed surprised by the maneuver. I was heartened by the seizure of the h3-c8 diagonal, which makes things more equal, and provokes Black's next move. Exchanging on d5 also would have been fine.} f5 20. Nc3 $6 {unfortunately at this point I had run out of ideas in the position. More active play would keep the balance.} (20. Bg5) (20. f4) 20... Bf7 $15 21. Nb5 Nd4 22. Nxd4 {effectively getting rid of the annoying outpost knight, as exchanging it is better than leaving the strong Nd4 in place.} Qxd4 23. Bg2 {bringing the bishop back into the game.} Nd5 24. Ne3 {another longer think without a good result. It's better to try to get the queen into the game, or at least more actively supporting the other pieces.} (24. Qe1) (24. Qc1) 24... Nxe3 (24... Nb4 $5 {would have maintained more pressure.}) 25. Bxe3 $6 {an example of stereotypical thinking, rejecting the idea of creating doubled pawns, which would actually give White a more dynamic position.} (25. fxe3 {I should have considered this more seriously, but was in significant time pressure by now.} Qd6 26. e4 $11) 25... Qd6 $17 {Black has a significant space advantage and better piece activity.} 26. Qc1 Rfe8 27. Rd1 Rbd8 28. Bg5 {this idea comes too late to be effective, as Black easily sidesteps with his rook.} Rd7 29. Bf1 $2 {a blunder, missing the danger the Bg5 is now in of being trapped.} Bd5 {luckily my opponent was also in similar time pressure and missed the refutation, giving me time to retreat it.} (29... f4 $1) 30. Bd2 Qc6 31. Bc3 (31. e4 {is actually possible and probably best here, due to the latent tactical possibility of a skewer on the a4-e8 diagonal.} fxe4 32. dxe4 Bxe4 33. Bb5 {and Black can only save himself by} Qf6 $11) 31... Qb7 32. f3 {playing it safe by blocking the diagonal, although the position is still very problematic for White.} e4 $6 {an attempt to force the situation in the center, which simply dissolves Black's pressure.} 33. Bxg7 Rxg7 34. dxe4 fxe4 35. f4 $11 e3 {after the last sequence, White should be equal now and out of the woods. I thought for a little while here, but was unsure of the best way to proceed.} 36. Qc3 Qc6 37. Rbc1 Rf7 38. Rd3 {this is a little slow.} (38. Qd3 $5) (38. Bh3 {reactivating the bishop.}) 38... Qe6 39. Rcd1 Rf5 40. Bh3 $2 {blunder at the time control. Another example of a good idea played too late, and in this case without considering my opponent's responses.} (40. Bg2 {was necessary.}) 40... Qe4 $1 {threatening mate on h1.} 41. Rxd5 {essentially forced.} Rxd5 42. Rxd5 Qxd5 $19 43. Bg2 Qd2 $6 {this allows White's next move, giving me a saving burst of activity against his king.} (43... Qd1+ 44. Bf1 Qd4 $19 {and the White pieces have nowhere to go.}) 44. Qc4+ $1 Kg7 45. h3 {giving the king an escape square, so the bishop would not have to go to f1 following a queen check.} (45. h4 $5) 45... Re7 46. Kh2 Qd4 47. Bd5 $2 {played in the (correct) expectation that Black would feel obliged to trade queens. However, the engine shows it would be better for White to keep the queens on.} (47. Qb5) 47... Qxc4 (47... b5 $1 48. axb5 Rd7 49. Be6 Qxc4 $19 {and now the endgame is winning for Black.}) 48. Bxc4 Kf6 49. g4 g5 50. Kg3 {low on time, my opponent offered a draw, believing I had a viable fortress. I thought it was not 100%, but it would have been difficult to break down. The engine considers Black the victor.} 1/2-1/2

17 February 2024

Annotated Game #265: The importance of a sense of danger

This second game from the tournament featured a Symmetrical English, which had a great deal of symmetry indeed, only varying on move 9. If one chooses to play as White in this way, then patience is the key to success, rather than an ability (or desire) to pursue an attacking, imbalanced game. It can be annoying when Black clearly has no experience with the opening, but can still get a good position simply by mimicking moves. However, sometimes the patient approach pays off, as in this game after Black gets impatient and presses too hard with his queen, at a time when a sense of danger was necessary.

[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "ChessAdmin"] [Black "Class C"] [Result "1-0"] [ECO "A38"] [Annotator "ChessAdmin/Dragon 3.2"] [PlyCount "148"] 1. c4 c5 2. Nf3 Nc6 3. g3 Nf6 4. Nc3 {the Symmetrical Four Knights} g6 {my opponent took some time in the opening and did not appear to be acquainted with the Symmetrical English, going for mimicing moves simply on principle.} 5. Bg2 Bg7 6. O-O d6 7. d3 {I seriously considered breaking new ground by playing d4 here, since Black postponed castling by a move, but eventually decided to stick with a position and strategy with which I was more familiar.} O-O 8. Rb1 {this scores best in the database, although I'm not sure how much difference move order makes for the basic plan, threatening b2-b4.} Bd7 9. a3 a5 {restraining the b-pawn advance} 10. b3 {with b4 having been prevented for now, I switch to a plan with a goal of swapping off Black's Bg7 and keeping the pressure on the light squares and center.} (10. Bd2 {is most played here, keeping White's options open.}) 10... Qc8 {choosing the common plan of seeking to exchange the Bg2.} 11. Re1 {choosing to keep the light-square bishop on the board, by clearing the diagonal so the bishop can retreat to h1.} Bh3 12. Bh1 h6 {controlling g5, otherwise Ng5 could harass the bishop on h3.} 13. Bb2 {following up on the plan decided on move 10.} Re8 {I thought for a long time here about what would be best to do. I looked at Nd2 as the other main candidate move, which is a standard maneuver to unlock the light-square bishop on the long diagonal. In ultimately choosing the text move, I preferred to maintain more control over the center and the d4 square. However, I did not see my opponent's response.} 14. Nb5 (14. e3 $5 {is another idea, suggested by Dragon 3.2}) 14... Na7 {here I could lock up the queenside with a4 and gain a bit of space, but I saw that I could force through b4 after the exchange, and preferred to try to open lines.} 15. Nxa7 Rxa7 16. Nd2 {it was between this or the immediate b2-b4, either of which are fine.} Bd7 {a surprise, but the obvious idea being to reposition the bishop on the long diagonal.} 17. Ba1 {played more out of minor frustration at not having anything apparently better. Now b4 seemed easier and I felt I was keeping my options more open.} (17. Bg2 $5 {has some value as a waiting move. The engine likes the plan of gaining space and restraining ...b5 by playing a4 afterwards.}) 17... Bc6 18. b4 Bxh1 19. Kxh1 Ng4 {this was also a surprise, threatening a fork on f2.} (19... axb4 $5 20. axb4 cxb4 {is tricky and would have been a better try for Black, perhaps. The point is that} 21. Rxb4 $2 (21. Kg1 $11) 21... Ng4 $1 {wins, due to the double attack on the Ba1 and the threatened fork on f2.}) 20. Kg2 {the idea being I could then play h3 to kick the knight.} Bxa1 {my opponent saw he could win a pawn here and became obviously eager to do it. However, the doubled b-pawns will offset the material gained with their weakness.} 21. Rxa1 axb4 22. axb4 Rxa1 23. Qxa1 cxb4 {I thought for a while here again, because I spotted the tactical issues with the weakness on f2 and Black's Q+N combination making threats.} 24. Qb2 (24. Rb1 $5 {is simpler and better, as the rook is much better employed on the b-file.}) 24... Qc5 25. d4 {played after long thought.} (25. Ne4 {I also considered, but ultimately was a little unsure of the Ne4's ability to defend in all variations.}) 25... Qh5 {a bit of a crude threat. Now for some reason I didn't even consider h3 to defend, in part due to some time pressure.} 26. Nf3 $11 {this is still good for equality.} Qa5 27. Ra1 {Black is out of immediate threats and now I felt good about taking over the initiatlve, although I still need to be careful with Black's queen still threatening to penetrate on the 2nd and 1st ranks in some variations.} Qb6 28. Ra4 b3 29. Ra3 {ready to safely round up the pawn and restore material equality.} Qb4 30. Nd2 {my opponent evidently did not consider this, which protects the c4 pawn and allows me to capture on b3 with the rook.} (30. Qxb3 {is even simpler.}) 30... Rb8 31. Rxb3 Qa5 32. f3 {finally kicking the Ng4 and also closing the long diagonal.} Nf6 33. Rb5 {played after some thought. I felt it kept more pressure up on Black and that the 5th rank was also a good place for the rook, if nothing else.} Qa4 {Black again threatens to peentrate with Qd1.} 34. Kf2 {protecting the e-pawn.} Qd1 $6 {Black plays this anyway, evidently hoping to go to h1. However this is over-ambitious and the queen has very few squares left.} 35. Nf1 {I felt this was the safe choice, as I did not have time to calculate out the situation after ...Qh1.} Kf8 $4 {Black is unaware of the threat to the queen.} 36. Ra5 $1 {sealing the queen's fate.} b6 37. Ra1 Qxa1 38. Qxa1 {White now has an easy win, but Black plays on almost until mate, hoping for a stalemate. I stay patient and "go to sleep" in the endgame, per Dan Heisman's advice, pursuing an inevitable winning strategy while avoiding any chance of stalemate.} Rc8 39. Ne3 e6 40. Qa7 d5 41. cxd5 Nxd5 42. Nxd5 exd5 43. Qxb6 Re8 44. Qd6+ Kg7 45. Qxd5 Re6 46. Qc5 Kf6 47. d5 Re8 48. Qc6+ Ke7 49. Qc7+ Kf6 50. d6 h5 51. d7 h4 52. d8=Q+ Rxd8 53. Qxd8+ Kg7 54. Qxh4 Kg8 55. e4 Kg7 56. e5 Kg8 57. Qf6 g5 58. Qxg5+ Kf8 59. Qh6+ Kg8 60. Qd6 Kg7 61. h4 Kh7 62. f4 Kg7 63. f5 Kh7 64. e6 Kh6 65. g4 f6 66. g5+ Kh5 67. Qd1+ Kxh4 68. g6 Kg5 69. e7 Kh6 70. e8=Q Kg7 71. Qf7+ Kh6 72. Qh1+ Kg5 73. Qg2+ Kf4 74. Qg3+ Ke4 {and my opponent decided he had suffered enough.} 1-0