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<18.??

The f5 and g5 set-up often suggests sacrifices on f6, h6, or g7. In addition, Black has two pieces protected by only the queen, so an overload theme is possible.

18.Bh6 was my first thought, but after 18...gxh6 19.Qxh6 f6, Black might be able to defend along the rank. So 18.Bf6 becomes the new candidate, stopping that defense and also setting up attacks on both of Black's half defended pieces.

18...Bxg2 is clever (19.Kxg2 Qc6+) but after 19.Nh6+ the knight is off limits and the rest is instructively forced.

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19 Bxb7 gxf6 20 Bxa8 Rxa8 could follow, leaving white up an exchange.

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But it's a perilous advantage because black both threatens a knight fork with check, winning the queen, and winning the knight directly, so white has to retreat the knight to h4.

You figured it all out, except that black has 22...Qxf6, winning a piece. That's why the queen has to stay put, to prevent 19...Ne2+.

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(A counter-attack with Qd7 may be recommendable here;

18. Bf6 Qd7 19. Bxb7 gxf6 20. Bxa8 Rxa8 21 Qf4 could follow. This leaves White an exchange up and his advantage is minimal.I do not think the game will take that long, winding road. Its more likely to be a short spectacle).

So I go with my prediction; <18. Bf6>. Black may see no danger and could insouciantly dally with the effete 18...Bxg2. And Nh6+ should follow.

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Time for Black to sit up and pay attention now.

<Bf6 Bxg2 19. Nh6+ Kh8 20. Bxg7+ Kxg7 21. Qg5+>

The caravan is here;

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Withdrawing the K is no good. The N could provide some fleeting comfort, so <21...Ng6>. <22. Nf5+> decides the issue. I do not think Black will push any further to the mate.

<18. Bf6 Bxg2 19. Nh6+ Kh8 20. Bxg7+ Kxg7 21. Qg5+ Ng6 22. Nf5+> 1-0

"Raise shields!" barked Captain Kirk, doing his best to suck in his ample gut.

"Too late I'm afraid," said a smoothly grey-suited man who suddenly appeared on the bridge of the Enterprise. He carried a neat clipboard, wore neat spectacles and his pencil moustache was - you guessed it - impeccably neat.

"What are you doing on my bridge?" demanded Kirk.

"Just a regular inspection of your transporter protocols, captain. I will not take but a moment. First, I would like to know why you insist on beaming down all of your senior officers to an alien planet? Leaving only Scotty in charge of the entire starship?"

"That does seem a logical question, captain," observed Spock dryly.

The inspector continued. "Then there's the small matter of security personnel wastage. Our records show that you've lost ... let me see, six this month? The accounts department are most upset."

"Damn it Jim, I'm a doctor not a miracle worker," grumped Bones, grumpily.

"But there's one thing that's been puzzling us," said the inspector. "You arrive at a planet, beam down straight away and yet wherever you land on the planet it's always daylight. Seems highly suspicious to me."

Today's POTD is all about transporter technology. Whether it's Jim's Qd5-f6 site-to-site transfer or the game's queen hop from the white transporter room on d2 to the thick of the action on g7.

Many chess combinations are about getting pieces into the right place at the right time. Today, white wants to get his queen to g7 in a hurry. So he is prepared to redshirt either his knight or bishop to do that. And the poor klingon pawn on g7 finds that he can defend h6 or g6, but not both at the same time.

<18.Bf6!> threatens not just captures on g7, but also Qg5, Qh6, Nh6+, and Ne7+ followed by Bxg7+

<Bxg2> 18...gxf6 19.Qh6

<19.Nh6+!> 19.Qg5?? Nf3+; 19.Qh6? Ne2+ 20.Kxg2 Qc6+ and 21...Qxf6

<19...Kh8> 19...gxh6 20.Qxh6

<20.Bxg7+! Kxg7 21.Qg5+ Ng6> 21...Kh8 22.Qf6#

<22.Nf5+ Kg8> 22...Kh8 23.Qf6+ and mate next

<23.Qf6! Qe5> stopping Qg7#

1) Nxg7

<18 Nxg7> is <18 ... Bxg2 19 Kxg2 Qb7+ 20 f3 f6! 21 Ne6 fxg5 22 Qxg5+ Ng3 23 Nxf8 Rxf8> who is winning?

or

2) Nh6+

<18 Nh6+> is <18 ... Kh8>

but what about something a little more quirky...

<18 Bf6! ...>

This sets up the classic B and N in the corner mate (I don't know its name), where the king has castled short and neither R nor K has moved since, the atacking B controls the long diagonal and the attacking N hops into h6 or h3 to give mate. (i.e. 18 ... g6 19 Nh6#)

18 ... gxf6 19 Qh6 mating?
18 ... Ng6 19 Qh6! mating?

So the only question is "<Once> the white queen has gone "walk-about" has black got a good counter-attack?

19 ... Nf3+ 20 Bxf3 and black is lost
19 ... Ne2+ 20 Kh1 Bxg2+ 21 Kxg1 Qc3+ 22 f3 and black is lost

So what replies has black got to <18 Bf6! ...>

18 ... Nf3+ 19 Bxf3 Bxf3 20 h4 Ne2+ 21 Kh2 solves nothing for black all it has done is delay the issue one move

18 ... Bxg2
19 Nh6+ ...
19 ... gxh6 20 Qxh6 mating
19 ... Kh8 20 Bxg7+ Kxg7 21 Qg5+ Ng6 22 Nf5+ Kg8 23 Qf3 Qe5 24 Nh6#

18 ... Rfe8 (trying to give the king some breathing room) 19 Nxg7!

18 ... Rfc8 19 Bxg7 winning a piece.

18 ... Rfb8 19 Rae1 threatening Re7 and then Nh6+!

I have no idea how black continues. It all looks gloom and doom for black.

The weakest point in black's position is the g7 square, black pieces are misplaced and cannot coordinate well in defense of their king in the case of an attack. White pieces has placed a battery of bishop+knight in the f5-g5 square, threatening the ennemy defenses. Consequently, it is logical to think that this position can be solved with a direct attack against the black king. However, if black has the time to play f6, his position will become much better. There are two possible strategies: straight attack or preparation ideas, each of them with a few alternatives:

1. Attacking now:
1.1. 18. Nxg7,…
1.2. 18. Nh6+,…
1.3. 18. Bh6, …
1.4. 18. Bf6, …
2. Attack preparation:
2.1. 18. Ne7+,…
2.2. 18. Be7,…
2.3. 18. Bf4,…
2.4. 18. Rfe1,…
2.5. 18. Rae1,…
2.6. 18. Bxb7,…
As there are ten possible ideas(18. Qf4, Ne2+), it is logical to begin by the direct attacking lines and calculate each one at time.

1.1. 18. Nxg7, Kxg7; 19. Bh6+, Kh8; 20. Qg5, f6, black rejects the attack and now threats a counter-attack beginning with Ne2+. 1.2. 18. Nh6+, Kh8, and there is no direct way to continue with the attack; black menaces a terrific counter attack with Bxg2.

1.3. 18. Bh6, gh; 18. Qxh6, f6, with advantage for black. 18. Nxh6+, Kh8; and follows f6, black is winning.

1.4. 18. Bf6! (goodbye forever to the alternative of f6), and now: 1.4.1. 18. …, gf; 19. Qh6, Ne2+; 20. Kh1, Bxg2+; 21. Kxg2, Nc6+; 22. f3, checkmate to follow. 1.4.2. 18. …, Nf3+; 19. Bxf3, Bxf3; (threats Ne2+) 20. Ne7+, Qxe7; (20. .., Kh8; 21. Bxg7+, Kxg7; 22. Qg5+, Kh8; 23. Qf6 mate) 21. Bxe7, Ne2+; 22. Qxe2, Bxe2; 23. Rfe1, Bg4; 24. Bxf4, Kxf8 and white keeps the exchange. 1.4.3. 18. …, Bxg2; 19. Nh6+ (19. Ne7+, Qxe7; 20. Bxe7, Nf3+; 21. Kxg2, Nxd2; 22. Tfe1 (22. Bxf8, Nxf1; 23. Bd6, Nd2; 24. Bf4, Ndb1, black wins), Tfe8; 23. Ad6, g5, with decisive advantage), Kh8 (19. …, gh; 20. Qxh6, Ne2+; 21. Kxg2, Qc6+; 22. _f3, Qxf6; 23. Qxf6 wins); 20. Bxg7+, Kxg7; 21. Qg5+, Ng6; 22. Nf5+, Kh8 (o Kg8); 23. Qf6, Ne2+; 24. Kxg2, Qb7+; 25. _f3, Ngf4+, 26. gf, Nxf4+; 27. Kh1, Ne6; 28. Nh6 checkmate. 1.4.4. 18. …, Ng6; 19. Bxg7 (19. Qh6, Ne2+ (19. …, gh; 20. Nxh6 checkmate); 20. Kh1, Bxg2+; 21. Kxg2, Qc6+; 22. _f3, Qxf6; black wins), Rfe8 (threats Ne2+); 20. Qh6, Ne2+; 21. Kh1, Bxg2+; 22. Kxg2, Ngf4+; 23. gf, Nxf4+; 24. Kg1, (24. Kf3, Ne6; 25. Qf6, Qf4+; 26. Kg2, Qg4+; 27. Kh1, Qf3+ =), Ne2+; 22. Kh1, Re6; 23. Bf6, Qc6+; 24. _f3, and there is an unstoppable checkmate in g7. If 21. …, Ne6, 22. Qf6, Nf4; 23. Ne7 checkmate.