1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6

These five moves make up the "Najdorf Variation" in the Sicilian Defense.

Black's last move seems to violate the principle of mobility,
since it develops no piece,
and the move has apparently no influence in controlling the center.
and yet the move is played by nearly all the masters
who use the Sicilian Defense against 1.e4.

Just watch in the coming moves what this pawn on a6 influences or makes possible....

6. Be3

Yes, other moves for White here are just as good.
It is a matter of taste ... part of what makes chess an art form....

e6

You could play e7 to e5 at once, but this is a different system....

7. g4 (?!)

This move is uncharacteristic of what we expect one GM to play against another.
It borders on the disrespectful, weakening the White kingside
and attacking violently when so many pieces are undeveloped.
With correct play Black crashes through...

and here is a great time to STOP!
and Find Black's Best Reply!!!

STOP - LOOK!

e5!

Yes! It breaks a 'rule' to move the same pawn two times in the opening,
much less moving it two times in two moves!

Of course the idea is to bring the bishop on c8 into the attack on g4....

8. Nf5 g6

Very well; Wojtkiewicz goes to work immediately to expose the weakness of the pawn on g4....

9. g5

Therefore White plays the best move available,
since moves of the attacked knight are losing.

gxf5
Black takes off the knight, and now GM Christiansen has to look
at the position that comes after taking the black knight.

[People with the Bookup version of this game will be able to examine the outcome if White simply takes back the piece.]

10. exf5?!

How to account for a move like this?
Seriously, how could a strong International Grandmaster just not take off the black knight?

Any theories out there???
Reply to: chessteacher@yahoo.com and your answer to the question [or suggestion] will be sent to: ChessCourse@yahoogroups.com when he returns in October from his travels. 

d5!

Fantastic. If White takes the knight now,
Black plays the fork ...d4 and is winning.

[See Bookup version of "ChessCourse" for what happens if White takes the knight at move 10, and what happens if the black knight makes his getaway at move 10.]

11. Qf3 d4

The problem is that in this line Black gets the fork anyway and remains a piece ahead... or am I missing something? ....

12. O-O-O Qc7

OK, so the queen just steps aside, and what has White for the knight he invested? ....

13. Bxd4

Strange as it seems, the move 13.Rxd4!? seems to give White drawing chances, whereas this move gives Black a large advantage.

(After 13.Rxd4 exd4 14.Bxd4, the knight on f6 is pinned by the bishop against the rook.)
[See the Bookup version for the 13.Rxd4 branch.]

exd4 14. gxf6 Nc6

Black is winning. With this pawn formation,
White's extra pawns are not worth a bishop.....

15. Bc4 Kd8!!

Now that strikes us as more than brilliant.
How many times have you moved your king while still in the opening,
losing the right to castle,
and onto a half-open file with an enemy rook at the other end of the file?!!!

We look at what happens if Black attacks instead with the natural move 15. ...Bh6+
[We look at that in the Bookup version.]

16. Kb1

Yes of course you notice that the black pawn is pinned against the king....

Bd7

So this move threatens to take the white knight....

17. Nd5 Qd6

Let's stop here and look for a move to save the game for White.
[In the Bookup version we look at 18.Nb6 to see if it holds the draw or not.]

18. Bb3 Rc8 19. Qh5 Qe5! 20. Qxf7 Qxf5

Do you see that Black threatens ...Ne5, trapping the white queen?

21. Rhg1?

Apparently White didn't see it, and again,
in the Bookup version we'll look into 21.Nb6.
This blunder fates White's seal.

Ne5

White might have resigned here with honor!

22. Qg8 Rxg8 23. Rxg8 Ng6

White could resign now and avoid the rush....

24. f4 Qe4 25. Ne7 Be6

Here White resigns, in view of the following....

26. Nxc8 Kxc8

The rook is trapped! Poor White!

27. Rg7 Nxf4

Did you think Black would take the bishop at g7?
Yes, that would have won also.

28. Bxe6+ Nxe6

Black wins easily now.

29. Rgg1 Qf4 30. Rgf1 Qxh2 31. Rde1 Qd6 32. f7 d3 33. cxd3 Qxd3+ 34. Ka1 Nd4 35. Re8+ Kd7 36. Ree1 Nc2+ 37. Kb1

Black has a choice here between Mate in Two and Mate in Three;
we'll look at the Mate in Three while the student finds a mate that is one move shorter!

Na3+ 38. Ka1
Mate in Two! Who doesn't see it???

Qb1+ !
of course.

39. Rxb1

Notice that taking the queen with the king is illegal.

Nc2#
Smothered Mate.