I played at the East Devon Chess Congress earlier this year alongside my longstanding friend and team-mate Charlie Keen. During a break between games, we went over one of his encounters, looking for tips for next time. The critical position was this one:
[Event "East Devon"] [Site "Exeter"] [Date "2013.03.03"] [Round "?"] [White "charles, keen"] [Black "terence, greenaway"] [Result "1-0"] [Annotator "Critical position"] [SetUp "1"] [FEN "r4rk1/2p2ppp/p1n2q2/1p2pP1n/1P2P3/P2BB2P/2P3PK/3RQR2 w - - 0 20"] [PlyCount "0"] 1-0
You might get more out of the discussion below, if you try and decide for yourself what you would play here.
Decided? Now read on...
This was the game to that point:
[Event "East Devon"] [Site "Exeter"] [Date "2013.03.03"] [Round "?"] [White "charles, keen"] [Black "terence, greenaway"] [Result "1-0"] [ECO "B07"] [Annotator "Game to that point"] [PlyCount "38"] 1. e4 d6 2. d4 Nf6 3. Bd3 e5 4. dxe5 dxe5 5. Nf3 Nc6 6. Nbd2 Bg4 7. h3 Bxf3 8. Nxf3 Bc5 9. O-O a6 10. a3 Qd6 11. b4 Bd4 12. Nxd4 Nxd4 13. f4 Nc6 14. Kh2 O-O 15. f5 Qd4 16. Rb1 b5 17. Qe1 Nh5 18. Be3 Qd8 19. Rd1 Qf6 1-0
Later I got this email:
"Please see attached, You had wondered if 23. fg was wrong, but in fact it turns out that 20. g4 was wrong, and the annotated variation starting 20. Be2 is the way to play this position. 20. g4 cost 150cp and nearly the game, but for the clock. You did not think twice about g4, nor did I. How to spot this sort of error in advance?"
Never one to let a rhetorical question lie, let's have a look, shall we?
This was the game continuation:
[Event "East Devon"] [Site "Exeter"] [Date "2013.03.03"] [Round "?"] [White "charles, keen"] [Black "terence, greenaway"] [Result "1-0"] [Annotator "Game continuation"] [SetUp "1"] [FEN "r4rk1/2p2ppp/p1n2q2/1p2pP1n/1P2P3/P2BB2P/2P3PK/3RQR2 w - - 0 20"] [PlyCount "29"] 20. g4 Nf4 21. Qg3 h6 22. h4 g5 23. fxg6 fxg6 24. g5 hxg5 25. hxg5 Qh8+ 26. Kg1 Rf7 27. Bxf4 Rxf4 28. Rxf4 exf4 29. Qxf4 Rf8 30. Qe3 Nd4 31. Be2 Nxe2+ 32. Qxe2 Qh4 33. Qg2 Qh5 34. Rf1 1-0
This was Fritz' recommendation, a pawn-and-a-half better in outcome, according to Charlie:
[Event "East Devon"] [Site "Exeter"] [Date "2013.03.03"] [Round "?"] [White "charles, keen"] [Black "terence, greenaway"] [Result "1-0"] [Annotator "Fritz alternative"] [SetUp "1"] [FEN "r4rk1/2p2ppp/p1n2q2/1p2pP1n/1P2P3/P2BB2P/2P3PK/3RQR2 w - - 0 20"] [PlyCount "37"] 20. Be2 $1 20... Nf4 (20... g6 $4 21. fxg6 Qxg6 22. Bxh5 Qxh5 23. Rf5 Qg6 24. Rg5) 21. Bf3 Qh6 22. Bg4 g5 23. g3 Nh5 24. h4 $18 24... Nf6 25. Bf3 Rad8 26. Kg2 Rxd1 27. Bxd1 Nd7 28. hxg5 Qd6 29. Rh1 Qe7 30. Rh6 Nd4 31. Qh1 f6 32. g6 Rf7 33. gxf7+ Qxf7 34. c3 Qa2+ 35. Bf2 Qf7 36. cxd4 Nf8 37. Qh4 c5 38. dxc5 1-0
[I will say my feeble old version of Fritz gives Charlie's move as +1.0 and the alternative as +1.5.]
1. Just to remark before getting stuck in, no chess player can be expected to get very far if they don't "think twice" about their moves, unless it is "QxQ checkmate". There are pros and cons about many moves, and often you have to take risks to beat opponents of a similar calibre to your own, so thinking more than once is recommended on occasion. (Chess is the art of creating positions that are too hard for your opponents, but if your opponent is as good as you are, there's probably an element of risk involved...) On the other hand, the clock is ticking, and there is pressure to play promptly, so let's make the natural moves quickly and think only when we have to...
2. Hindsight is a great teacher. Let's look at the pros and cons of that move 20.g4:
PRO: Grabs space on the King's-side Prepares to grab more space on the King's-side Prepares to open lines on the King's-side Gains time by attacking the Knight Forcing (so easy to analyse)
CON: Abandons pawn control of f4 Prepares to open lines on the King's-side (they are two-way streets!)
We can see with hindsight that the cons of the game continuation did become manifest on the board. Thinking this way, hindsight today might become foresight tomorrow. We might, indeed, spot the error in advance.
3. Is there anything general, and generalisable, that we can say about the incorrect text move? And is there anything general, and generalisable, about the correct Fritz suggestion?
If you had to describe the theme of the game, we might file it under Attacking the King castled on the same side, which presents problems when we are trying to open lines.
We can see in the Fritz line that Black got some counterplay when the Black Queen was able to occupy the h-file before White.
Moreover, if you contrast the White and Black campaigns, you might say Attacker and Defender. But let's refine this to: Attacking with Bishops and Defending with Knights.
In the game, Black's Knight, solidly placed on f4, was a real nuisance to White. We can also see in the Fritz line something of the generally recommended strategy for fighting with Bishop(s) against Knight(s), namely, the Knights must be denied stable squares. Here's the technique in a fairly pure form, although Steinitz later chose to swap the advantage of Bishop over Knight for other chances:
[Event "bishops: two bishops in semi-o"] [Site "bishops: two bishops in semi-"] [Date "????.??.??"] [Round "?"] [White "Englisch"] [Black "Steinitz"] [Result "0-1"] [ECO "C60"] [PlyCount "86"] 1. e4 e5 2. Nf3 Nc6 3. Bb5 g6 4. d4 exd4 5. Nxd4 Bg7 6. Be3 Nf6 7. Nc3 O-O 8. O-O Ne7 9. Qd2 d5 10. exd5 Nexd5 11. Nxd5 Qxd5 12. Be2 Ng4 13. Bxg4 Bxg4 14. Nb3 Qxd2 15. Nxd2 Rad8 16. c3 Rfe8 17. Nb3 b6 18. h3 Be6 19. Rfd1 19... c5 { Already denying the Knight a central square. This is the recipe: the Knight more than any other piece needs a secure advanced and/or central post. So Black keeps the Knight from settling and works his way in using the long-range threats of the Bishops.} 20. Bg5 f6 21. Bf4 Kf7 22. f3 g5 23. Rxd8 Rxd8 24. Be3 h6 25. Re1 25... f5 $1 { White doesn't want to allow f5-f4, but doesn't want to play f3-f4 either!} 26. f4 Bf6 27. g3 a5 28. Nc1 a4 29. a3 Bc4 30. Kf2 { Black is now rather better.} 30... gxf4 31. Bxf4 31... Bg5 {Black chooses to go into a B vs N endgame. The side with the two Bishops usually has a choice about how to change the position, swapping one advantage for another.} 32. Bxg5 hxg5 33. Ke3 Kf6 34. h4 gxh4 35. gxh4 Re8+ 36. Kf2 Rxe1 37. Kxe1 37... Ke5 { Black's better King wins the game.} 38. Ne2 Bxe2 39. Kxe2 { Both Bishops have disappeared, but Black is winning.} 39... Kf4 40. c4 Kg4 41. Ke3 41... f4+ {!} 42. Ke4 f3 43. Ke3 43... Kg3 {0-1 englisch-steinitz} 0-1
With that discussion in mind, the strength of the Fritz line, and the principles that underlie it, becomes clear. White builds up more slowly, denying the Knight a place to squat, and not opening the position to the risk of our own King. And, I hope, this sort of reflection is what might help us spot such errors in advance.
4. What, in the end, is the lesson of this game? Perhaps it's more than something about Bishops and Knights, viz.: just as rehearsing tactical examples widens the variety of tactical opportunities (and mistakes) that we are likely to notice at the board, familiarity with a wide variety of strategical examples is likely to do the same thing for our positional decisions.
Comments invited!