There are many different ways to categorize chess positions. One way is to use the analog-digital-dualism. Analog positions are more frequent. Here, the advantage gradually passes from one side to the other, subject to the mistakes committed. In digital positions, there often is only a very fine line between victory and defeat or, to put it more moderately, between a distinct advantage on either side.
Since the following game is a King’s Indian, I want to give an example from this rich opening. In the main line with 9.Ne1, Black usually attacks on the kingside while White is trying to tear apart Black’s queenside structure. Very often, the quicker side will win the game. It’s a binary or digital situation where the space for a draw is rather slim. In the actual game, we will see a different situation, since White refrained from 9.Ne1. However, the position still is digital in nature. The digitalizer here is a far advanced passed pawn. As we know, such pawns are either very strong or very weak, and there is not much space in between.
[Event "Tastrup"]
[Site "Tastrup"]
[Date "1992.??.??"]
[Round "?"]
[White "Gurevich, Mikhail"]
[Black "Wahls, Matthias"]
[Result "0-1"]
[ECO "E97"]
[WhiteElo "2635"]
[BlackElo "2570"]
[Annotator "Wahls"]
[PlyCount "116"]
[EventDate "1992.02.??"]
[EventType "tourn"]
[EventRounds "9"]
[EventCountry "DEN"]
[EventCategory "13"]
[SourceDate "2002.05.06"]
1. d4 Nf6 2. c4 g6 3.
Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6 8. d5 Ne7 9. Nd2 {Diagram [#]
This was a popular line with all those, who didn't like the notion of
getting mated in the sharp variations arising after 9.Ne1. Later, the majority
concluded that it might be more logical to realize this idea with 9.b4
(Bayonett Attack), in order to retain the option of Ng5 after Black played f5.}
a5 10. a3 Nd7 11. Rb1 f5 12. b4 Kh8 $1 {[%cal Ge7g8,Gg8f6] Diagram [#]
Kasparov's discovery. Instead of playing the automatic 12..Nf6, Black invests
a tempo to solve the problem of his bad knight on e7 while maintaining the control
over c5 by his colleague.} 13. Qc2 Ng8 14. exf5 {A dynamic alternative to 14.f3,
which has been played roughly as often and was the mainline back in 1992.} gxf5
15. f4 {The mobile black pawn centre has to be blocked.} Ne7 $1 {Diagram [#]
This move was applied three times by Fishbein in Kerteminde 1991 - with a
success rate of 100%. It found a lot of followers and is still popular today.}
(15... exf4 $6 16. Nf3 Ne5 17. Bxf4 $14) (15... e4 $2 16. Nb3 {[%cal Gc1e3,
Gb3d4,Gd4e6] is clearly better for White}) 16. Nf3 (16. fxe5 Nxe5 17. Nf3 Nxf3+
18. Bxf3 Ng6 $10 {K.Berg-Fishbein, Kerteminde 1991}) 16... axb4 17. axb4 e4 $1 {
Fishbein's actual discovery. Before, 16..Ng6 17.Ng5 Nf6 18.fe5
de5 led to an unclear position.} 18. Ng5 (18. Ne1 c6 $11) 18... Nf6 19. Rd1 {
Diagram [#] This move is directed against the undermining 19..c6 and was a
novelty at that time.} (19. Kh1 h6 20. Nh3 c6 $13 {Van der Sterren-Fishbein,
Kerteminde 1991}) (19. Bb2 c6 20. dxc6 bxc6 21. Rfd1 Qc7 $1 22. Qd2 h6 23. Nh3
Rd8 $13 {Schirow-Fishbein, Kerteminde 1991}) 19... c6 {Unimpressed by White's
last move, I follow the standard undermining plan.} 20. Be3 h6 $1 {Diagram [#]
Not fearing the generation of a passed pawn on e6. Such a pawn generally is
either very weak or very strong. I saw it more on the weak side, after doing a
lot of calculations, of course.} 21. Ne6 (21. Nh3 $6 cxd5 $1 22. Nxd5 (22. cxd5
Ng4 23. Bxg4 fxg4 24. Nf2 Nf5 $17) 22... Nfxd5 23. cxd5 Bd7 24. Qd2 Ra3 25. Bd4
Rg8 26. g3 Ba4 $36) 21... Bxe6 22. dxe6 Nc8 {The idea is to get hold of the
intruder by Qe7xe6. However, White's next move had to be anticipated already when 20..h6 was played.} (22... Ne8 $2 23. Bh5 $1 $14 {followed by Bf7}) 23. g4
{Diagram [#] Gurevich relied on this pawn break, evidently overlooking my very
next move......} Qe8 $3 {A small move with a big effect! It is important to
keep the square e7 vacant for the knight.} (23... fxg4 $2 24. Nxe4 Qe7 25. f5
$18) (23... Nxg4 24. Bxg4 fxg4 25. Nxe4 Qe7 26. Bd4 Qxe6 27. Bxg7+ Kxg7 $11) (
23... Ne7 24. Bc5 (24. Kh1) 24... Ne8 25. Kh1 Qc7 26. Bg1 $14) 24. gxf5 (24. g5
$2 hxg5 25. fxg5 Nh7 26. Qd2 Qxe6 $17) 24... Ne7 $1 {This sequence was hard to
see. Not only didn't I prevent gxf5 from happening, I additionally abandon the defense of
my d6-pawn.} 25. Nxe4 (25. Rxd6 $2 Nxf5 $19) 25... Nxf5 {Diagram [#] The
knight made quite a career from the back rank defender of a pawn to the proud
vanguard of Black's position.} 26. Bf2 (26. Nxd6 $2 Nxe3 27. Nxe8 Nxc2 28. Nd6
Ne8 $1 29. e7 Nxd6 30. exf8=Q+ Bxf8 31. Rd2 Ne3 $17) (26. Bb6 c5 27. Ng3 Ne3
28. Qd3 Nxd1 29. bxc5 dxc5 30. Rxd1 Qxe6 31. Bxc5 Rf7 $15) 26... Nxe4 $1 {
This has the virtue of deflecting the queen from protecting a2.} (26... Qxe6
27. Ng3 Ne3 28. f5 Qe5 29. Bxe3 Qxe3+ 30. Kh1 $13) 27. Qxe4 Qg6+ 28. Qg2 (28.
Kh1 $4 Ng3+ $19) (28. Bg3 $2 Ra2 29. Rb3 Rg8 $17) 28... Qxe6 {Diagram [#]
Finally, the passed pawn is history. As it is plain to see, I am in command of
the more active pieces now.} 29. Qf3 $2 {My power play takes its toll. Gurevich
stumbles under pressure.} (29. Bd3 Ne3 30. Bxe3 (30. Re1 $2 Nxg2 31. Rxe6 Nxf4
32. Re3 (32. Rxd6 Nh3+ $19) 32... Bd4 $19) 30... Qxe3+ 31. Kh1 Rxf4 $15) 29...
Ra2 30. Bf1 (30. Re1 $2 Bd4 31. Kh1 Bxf2 32. Qxf2 Re8 33. Bg4 Rxf2 34. Rxe6
Rxe6 35. Bxf5 Ree2 $19) 30... Nd4 $1 $17 {Diagram [#] The knight crowns its
journey by giving its live for a higher cause.} 31. Bxd4 (31. Qg3 $2 Qe4 32.
Bd3 Qxf4 33. Rf1 Rd2 34. Qxf4 Rxf4) (31. Qe3 $4 Qxe3 32. Bxe3 Nf3+ 33. Kh1
Rxh2#) (31. Rxd4 $4 Qg6+ 32. Kh1 Qxb1 $19) 31... Bxd4+ 32. Rxd4 $2 {Apparently,
32.Kh1 was too passive for his taste and he was hoping for counterplay.} (32.
Kh1 Rf2 33. Qh3 Qxh3 34. Bxh3 Be3 35. Rf1 Rc2 $17) 32... Qg6+ 33. Qg3 Qxb1 34.
Rxd6 Qh7 (34... Rg8 $4 35. Rxh6+ Qh7 36. Rxh7+ Kxh7 37. Bd3+ Kh8 38. Bg6 $18)
35. f5 (35. Rg6 $2 Qxg6 36. Qxg6 Rg8 $19) (35. Bd3 $2 Qg7 36. Qxg7+ (36. Rg6
Qd4+ 37. Kh1 Ra1+ 38. Kg2 Rg1+ $19) 36... Kxg7 37. Rg6+ Kf7 38. Rxh6 Rg8+ 39.
Kf1 Rgg2 $19) 35... Rg8 36. Rg6 Rxg6 37. fxg6 Qe7 $19 {Diagram [#] Problem
solved. The rest is a matter of technique.} 38. Qc3+ Qg7 39. Qd3 Qe5 40. Qd8+
Kg7 41. Qd7+ Kxg6 42. Qd3+ (42. Bd3+ Kg5 43. Qd8+ Kh5 $19) 42... Kf7 $6 (42...
Kg5 43. Qd8+ Kh5 44. Qd1+ Kh4 $19) 43. Qd7+ Qe7 44. Qd4 Qg5+ 45. Kh1 Rd2 46.
Qe4 Qg6 47. Qe3 (47. Qf4+ Qf6 48. Qxd2 Qxf1#) 47... Qf5 $1 48. Be2 Rb2 $6 (
48... Qb1+ 49. Kg2 Qxb4 $19) 49. h4 Rxb4 50. Bh5+ $5 Qxh5 51. Qf2+ {No matter,
where the king moves, White will pick up the rook. The queen ending, however,
is hopeless.} Ke6 $1 52. Qe1+ Kd7 53. Qxb4 Qxh4+ 54. Kg2 Qg4+ 55. Kh2 Qh4+ 56.
Kg2 Qg4+ 57. Kh2 Qf4+ {Covering d2.} 58. Kg2 b5 0-1
