After 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6, White can prepare to reach the Averbach system of the King’s Indian by playing 5.Be2. The Averbach is a flexible system for White that allows him to go in many different directions afterwards. Often he can castle on either side of the board. White can play purely positional or try to launch a sharp kingside attack. This line is therefore suited to meet the preferences of most players.
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After 5…O-O, Black’s normal means of counter play in the Averbach are similar to most King’s Indians. He will choose to challenge White’s center with either …c7-c5 or …Na6 followed by…e7-e5 and try to open a file in the center. Our chosen line of play follows the path of a game of former World Champion Boris Spassky in which he took advantage of an error of his opponent Judith Polgar.

6.e5? attacks Black’s f6-knight, but advancing the e4-pawn early in the Averbach does not work out well. After 6…dxe5 7.dxe5 Qxd1+ and …Ng4 to follow, Black would stand well.

6.d5?! may transpose to other main lines later on, but is not most accurate. Try to develop a new piece now and wait to see how Black will try to challenge your center before you make such a committing move.

6.Nf3 leads to the King’s Indian main line. We will be looking at the many branches of it in other challenges of this module. Good, now develop the c1-bishop to the most aggressive post to reach the Averbach instead.

6.Bg5 is the move that makes this the Averbach. White could have reached the King’s Indian main line by playing 6.Nf3 or the Four Pawns Attack with 6.f4. Less advisable was 6.f3, since the light-squared bishop is not well placed on e2 in a Saemisch. By delaying the development of the g1-knight in the Averbach, White controls g4 and has the added options to advance the f2-pawn first and develop the g1-knight only after Black has revealed his plans.

Black has to make a decision how he will go about challenging White’s pawn center. 6…c5 tries to open the long a1-h8 diagonal for Black’s bishop on g7 and prepares counter play on the queenside. Black has done quite well with 6…Na6 at this point. This move typically prepares the …e7-e5 advance. White should stay away from 7.Qd2 against 6…Na6 and choose either 7.f4 or 7.h4. The sharp 7.h4 was played in Bareev-Kasparov (1992). Following 7…h6 8.Be3 e5 9.d5 Nc5, play was unclear. Instead 7…e5 8.d5 Qe8 9.h5 Nc5 10.h6 was better for White in Kachiani-Machelett (1998). We like the move 7.f4. Following 7…c6 8.Nf3 Nc7 9.Bh4, White had a strong presence in the center and was ready to advance with e4-e5 next in the game Yakovich-Schlosser (1993). We will observe the 6…Na6 system in another challenge of this module from Black’s point of view.
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Your focus should be on the action in the center.

7.d5 gains more space in the center and is White’s main continuation. White has also reached fine results with the capture 7.dxc5. Black must then avoid 7…dxc5? 8.Qxd8 Rxd8 9.e5, and Black will lose the e7-pawn next. Following the better 7…Qa5 8.Bd2 Qxc5 9.Nf3 Bg4 10.0-0, White would have a small edge. 
Less promising would have been 7.Nf3, when both 7…cxd4 8.Nxd4 Nc6 and 7…Qa5 8.0-0 cxd4 9.Nxd4 Nc6 would allow Black to reach a favorable version of the Maroczy bind.

7…h6 tests White’s intentions and gives Black the chance to maintain control of h6. White would usually meet 7…e6 with 8.Qd2, when …h7-h6 is no longer an option. Often Black seeks counter play on the queenside right away. However, both 7…a6 8.a4 e6 9.Qd2 and 7…b5 8.cxb5 a6 9.a4 Qa5 10.Bd2 are fine for White.
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While considering your move now you should try to envision how Black may try to challenge your center next and how you will go about improving your position.

8.Bxf6? hands over control of the dark squares to Black after 8…Bxf6. Taking Black’s f6-knight with your dark-squared bishop is hardly ever a good idea in the King’s Indian.

8.Bh4 is a fine move that keeps the pressure on Black’s f6-knight. Then 8…e6 9.Nf3 leads to different types of positions. We slightly prefer a different retreat square along the h6-c1 diagonal.

8.Be3 is one of several fine bishop retreats in this position. White can also play 8.Bh4, when 8…e6 9.Nf3 leads to different types of positions. The most aggressive and ambitious choice is 8.Bf4, which pressures the d6-pawn and seeks to discourage Black from advancing with …e7-e6 next. Often Black sacrifices the d6-pawn by continuing with 8…e6 nevertheless. Then 9.dxe6 Bxe6 10.Bxd6 Re8 11.Nf3 and 10.Qd2 Qb6 11.Bxh6 both slightly favor White. Perhaps Black should try to improve with 8…Qa5 and meet 9.Qd2 with 9…e5. Then 10.dxe6 Bxe6 11.Bxd6 Rd8 looks like a reasonable line for Black. 
Clearly White should avoid both 8.Bxf6?, giving up the dark-squared bishop, and the awkward 8.Bd2?!, which gets in the way of White’s other pieces and makes it much harder to play the same plan as in our line.

8…e6 is Black’s normal means of seeking counter play. He has to exchange a pair of pawns to open some files and diagonals for his otherwise lifeless pieces. Black instead tried the aggressive 8…b5 in Donner-Ivkov (1972), but White maintained an edge following 9.cxb5 a6 10.bxa6 Bxa6 11.Nf3.
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White now has several very different options to choose from.

9.e5 dramatically changes the pawn structure in the center. Following the forced 9…dxe5 10.Bxc5 Re8, White can get a passed d-pawn with 11.d6. He would then have a four against two pawn majority on the queenside, while Black has a potential pawn avalanche on the kingside. Play is usually unclear after Black blocks the d6-pawn with his f6-knight. We slightly prefer a more conventional plan.

9.Nf3 is playable, but gives up control of the g4-square for a moment. After 9…exd5 10.exd5 (or 10.cxd5) Ng4 11.Bd2 f5, Black would have enough counter play.

White has done quite well by changing the pawn structure in the center with 9.dxe6 Bxe6. He could then pursue similar plans as in our main line. While this is interesting, we have chosen another path.

9.Nb5?? moves this well-placed knight again and to a poor square where Black can always kick you back with …a7-a6. Black could now win your e4-pawn with 9…Nxe4. Better look again.

9.Qd2 gets the queen to the best square in this system. White now attacks Black’s h6-pawn a second time. Play would likely transpose to our line soon after 9…exd5. Good, we have chosen to first gain more control of the g4-square.

White usually has to play h2-h3 sooner or later in this system. Doing so now with 9.h3 clearly shows how White intends to recapture in the center once Black takes on d5. White could have also continued with 9.Qd2 now and pressured Black’s h6-pawn right away. Play could then transpose to our line a bit later. 
White had two unusual alternatives in 9.e5 and 9.dxe6.

Play following 9.e5 dxe5 10.Bxc5 Re8 11.d6 would be unclear, but Black shouldn’t have any serious problems since he can easily block White’s pawn majority on the queenside. But 9.dxe6 Bxe6 has done very well for White. Following 10.Qd2, White then often follows a somewhat similar plan as in our main line although the pawn structure is quite different.

By taking White’s d5-pawn with 9…exd5, Black right away continues with his plan of seeking counter play in the center. There were no pressing alternatives. Black will also find it easier to come up with a plan once he sees how White recaptures on d5.
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The pawn structure often determines where the other pieces can go.

10.exd5 is clearly the better capture in this case. Generally, recapturing on d5 with the e4-pawn is considered less ambitious because White does not try to gain a pawn majority in the center. But in a situation where the e4-pawn would become a quick target, White should not take with the c4-pawn on d5. 
Had White taken on d5 with 10.cxd5?!, Black would get a quick initiative with 10…Re8 and could pressure the e4-pawn further with …Qe7. Protecting the e4-pawn with f2-f3 after White already has played h2-h3 creates too many dark-squared weaknesses on the kingside. After e.g., 11.f3 Nh5, Black would stand better.

10…Re8 places this rook on the open e-file right away and hopes to create some pressure against White’s uncastled king soon. In an earlier game in 1991 Judith Polgar tried 10…Bf5 instead against Hort. But after 11.g4! Bc8, White gained a full tempo compared to the plan in our line.
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This pawn structure can lead to rather boring positions when a lot of pieces are exchanged soon. We have a more ambitious plan in mind.

11.Qd2 is the most flexible continuation and tries to pressure Black’s kingside. The more conventional 11.Nf3 instead allowed Black to exchange a pair of knights in the game Yermolinsky-Edelman (1993) following 11…Bf5 12.0-0 Ne4. White still had a small edge, but the position was rather quiet. 
White can also consider moving the e2-bishop to d3 now to stop Black from playing …Bf5 next. After 11.Bd3 Nbd7 12.Nf3 a6 13.a4 Qb6, White had a small edge in Tatai-Donner (1971).

Black ignores White’s idea and instead prepares to launch a counter attack on the queenside with 11…a6? This is quite risky and the source of Black’s trouble in our line. After the better 11…Kh7, White gained an edge with 12.Bd3 Na6 13.Nge2 in the game Polugayevsky-Jansa (1970). Black has done better with 12…b5, when 13.cxb5 Nbd7 14.Nge2 Ne5 15.Rd1 a6! gave Black enough counter play for the pawn in Tisdall-Hellers (1992). Also 13.Nxb5 Ne4 gives Black some compensation for the pawn.
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Since this may be the most critical point of this line, the positions after 11…Kh7 12.Bd3 need to be further analyzed.

12.Nf3 is a solid way of continuing development, but is not most ambitious. You should now consider a more active option on the kingside. If that one is not favorable for White, then you need to consider Black’s planned counter play on the queenside with …b7-b5 to come soon.

12.Bxh6 challenges Black to justify her pawn sacrifice. This is clearly the only way to fight for a clear advantage since 12.a4 Kh7 allows Black to reach more solid positions.

By playing 12…Bxh6, Black tries to take White’s queen away from the center of the board and gain strong counter play there. But this move also has substantial risks as it brings White’s queen close to Black’s king.
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There is no going back once you enter sharp tactical lines.

13.Qxh6 is the only reasonable move

13…b5 tries to undermine the support of the d5-pawn and open files on the queenside and leading to White’s king.
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If White could get more pieces to aid the queen in her efforts against Black’s monarch, White could soon gain a strong kingside attack.

14.b3? protects the attacked c4-pawn, but taking on c4 is not a dangerous threat. You should be more concerned about Black playing moves such as …Bf5, …b4 and …Qe7 next.

14.Nf3! doesn’t mind Black’s queenside activity and simply develops a new piece closer to the center of action. Now White can consider castling on either side of the board, depending on how Black will continue. 
Note that White could have also opted for 14.a4!?. This interesting move forces Black to make a decision what he wants to do on the queenside. Since taking on a4 or c4 is harmless, 14…b4 is best. Then 15.Nd1 leaves White in the driver’s seat, e.g., 15…Ne4 16.Nf3 Qf6 17.0-0. Also 14.h4 was worth considering, but Black holds on with 14…Ng4.

14…Qe7?! increases the pressure against the pinned bishop on e2. Although Black now threatens to win a piece by advancing the b5-pawn to b4 in some lines, 14…Qe7?! is inaccurate. Note that taking on c4 instead with 14…bxc4? allows White to castle on either side of the board. Instead 14…b4 15.Nd1 with the idea of Ne3 also leaves White on top. 
Black’s best alternative appears to be 14…Bf5!?, with the idea of moving this bishop to d3 next. Since castling either side would then lose a piece to 15…b4, White has to make some defensive moves starting with e.g., 15.Qd2. Then g2-g4 and castling queenside is looming. Black would have some compensation following 15…b4 16.Nd1 Qe7 17.Ne3 or 16…Ne4 17.Qf4, but it doesn’t seem to be quite enough for the pawn.
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The queen on e7 now blocks the escape route of the Black king in some lines.

Castling kingside with 15.0-0?? now loses a piece after 15…b4. If White then moved the attacked c3-knight, Black’s queen could win the bishop on e2. Also 16.Bd3 bxc3 17.Bxg6 fxg6 18.Qxg6+ Qg7 does not give White any attacking chances against Black’s monarch.

Castling queenside with 15.0-0-0?? now loses a piece after 15…b4. If White then moved the attacked c3-knight, Black’s queen could win the bishop on e2. Also 16.Bd3 bxc3 17.Bxg6 fxg6 18.Qxg6+ Qg7 does not give White any attacking chances against Black’s monarch. While queenside castling may be desirable in many lines, it needs to be prepared better.

15.cxb5? axb5 opens more lines leading to White’s position. This will also make it much harder to safely castle on the queenside later on. You would then still have to deal with Black’s threat of playing …b5-b4 next.

15.Ng5! takes advantage of Black’s inaccurate queen move to e7. White now eyes the h7-square and thus ties Black’s f6-knight to defending against a mate. White still couldn’t have castled either side since after 15…b4, Black would gain the e2-bishop once the attacked c3-knight moves.

15…Bf5 controls the e4-square again and thus tries to stop White from getting the c3-knight to e4 in many lines. If 15…b4, then White reveals the main idea of 14.Ng5! by playing 16.Nce4. Then Black clearly has to avoid 16…Nxe4?? 17.Qh7+ Kf8 18.Qh8 mate. This is why the queen move to e7 was inaccurate. After the better 16…Bf5, White could keep an edge with 17.Ng3 Bd3 18.0-0-0! or 17.f3.
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White’s queen appears to be out of play now and White’s king is stuck in the center. Has White miscalculated?

16.g4! encourages Black to make the move he wants to play anyway. But this is White’s only reasonable continuation and fights for control of the e4-square. A passive bishop retreat to d7 or c8 would then allow White to castle queenside next and meet …b5-b4 with Nce4 again. So Black must enter the forced tactics with 16…b4 or play 16…Bd3. Advancing with 16…b4 forces 17.gxf5 bxc3. Then White has the same problem of how to stop the mate threat on e2. But the beautiful 18.Ne6!! blocks the e-file, threatens mate on g7 and opens the g-file for White’s pieces following 18…fxe6 19.Rg1. Then both 19…Nh7 20.Rxg6+ Kh8 and 19…Qh7 20.Rxg6+ Kh8 21.Rxf6 clearly favor White. You can be sure that Spassky saw most of this when he played 16.g4 or even earlier. 
For this reason Polgar played 16…Bd3 instead of 16…b4 and attacked the e2-bishop again. Then White seems to be losing a piece as the pinned e2-bishop cannot be given more protection. But following 17.0-0-0!, White again turns the tables on Black. After 17…Bxe2 18.Rhe1, White now pins the e2-bishop and will regain the piece soon. Then 18…Bxd1? 19.Rxe7 Rxe7 20.Kxd1 is clearly better for White. In the game Spassky-J. Polgar (1993), Black tried to minimize the damage with 18…Qf8, which forced queen trade with 19.Qxf8+ Kxf8. Then 20.Rxe2 Rxe2 21.Nxe2 gave White a much superior endgame, which the former World Champion easily converted to victory. 
We just learned one of the main lines of the Averbach by following a game of two very strong grand masters. Once Black erred with 11…a6?, White was able to use several nice tactics to make sure he maintained a superior position with the extra pawn. It is rare that play is so tactical in Averbach lines where White recaptures on d5 with the e4-pawn. This was mainly due to Black’s early mistake.

Had Black played the superior 11…Kh7, a longer positional battle would have lied ahead. Black’s best chance to reach more dynamic chances is by playing the 6…Na6 system. We will observe this system in another challenge of this module from Black’s point of view. White can also vary from our line by playing either 7.dxc5, 8.Bf4 or 9.dxe6.