So, back to 30.Qxh7+ Bxh7 (forced) 31.Rxh7+ Kf6 32.Rhg7 (this is the key move)

Now, mate is threatened by 33.R5g6# and is unavoidable

There's so much going on in this position. But I keep getting drawn back to...

30 Qxh7+

This seems like it must be correct. After

30...Bxh7 31 Rxh7+ Kf6

The black king is naked, and exposed to white's pieces. This is where the "hard to find" move must be. I would like to propose

32 Rhg7

The king is now totally bottled up. White threatens 33 R5g6#, and I don't see a good way to stop it. If black wants to play on, he must try

32...Qe8

but after

33 Nxe8+ Ke6

On 33...Rxe8 34 R5g6# is checkmate.

34 R5g6+ Nf6

Or 34...Rf6 35 Re7# is also mate.

35 Rxa7 Rxe8 36 g5 Rf8 37 Rxf6+ Rxf6 38 gxf6

leaving white up a rook and a bishop.

Visualizing the followup 32. Rhg7! is the key to solving the puzzle. For novices, finding such moves is often the most difficult aspect of combination play. Checks, captures and mates are easier to see. However, those relatively quieter moves that threaten mate or decisive win of material or mate are sometimes more difficult to visualize, especially when they follow a series of more obviously forcing sham sacrifices, checks and captures.

White to play (30.?) "Medium"

This is one of my favorite tactical themes - the surprise move or sacrifice (often the queen), followed by a "quiet" move. Most people would look at the queen sacrifice here, but not seeing the follow-up (quiet move), they would move on to something else or give up. In this case, you would tend to keep looking for the quiet move after the queen sac, because nothing else comes close to working!

30. Qxh7+! Bxh7

Of course, the only other option is 30...Kf6 31. Qxg6# (or Rxg6#).

31. Rxh7+ Kf6 32. Rhg7!

The quiet move. Now White threatens 33. R5g6 mate, and taking White's knight doesn't help, so Black must sacrifice his own queen to delay mate, but that is only a delay "tactic".

32...Qe8 33. Nxe8+ Rxe8 (or 33...Ke6 34. Re7#) 34. R5g6#.

28.Rxg6 Qxh4 (28...hxg6 leads to a quick mate) 29.Rxh4 hxg6 30.Rh7+

And here 30...Kf6 loses a Knight and allows a passed pawn while 30. ...Ke8 allows a Knight fork to win a rook.

As for the actual puzzle, I think the noob move works here as well (please correct me if I'm wrong!)

30.Rxg6 Qxh4 (as before, hxg6 loses.) 31.Rxh4 hxg6 32.Rh7+ Kf6 33.Rxd7

1. castle early and clear the back ranks so that the rooks can talk to each other.

2. park one of the rooks at the foot of an open file, a semi-open file or a file that is likely to become open or semi-open.

3. increase its strength on that file by doubling up with another rook or a queen, or preferably both.

4. when you can, use the file (and the support of your other pieces) to invade the enemy position, usually on the seventh rank. If necessary, sac material to get there.

5. once on the seventh rank, combine with other pieces to mate the enemy king.

Interestingly, four of these five stages rely on the cooperation with another piece. This is often, but not always, a fellow rook. Two rooks working together more than double their power.

In today's puzzle, there are two moves that allow white to play a rook to the seventh rank. I first looked at 30. Rxg6, but after 30...Qxh4 31. Rxh4 Kxg6 I couldn't make any more progress. Switch to plan B.

30. Qxh7+ Bxh7 31. Rxh7+ Kf6

click for larger view

From here there are at least two ways to win. The most efficient is 32. Rhg7 (as played) which sets up the unstoppable threat of 32...R5g#. Or we could play the typical rook move of 32. Rgg7

click for larger view

Black is forced to give up huge amounts of material to prevent the immediate g5# or the plan of c5/ Bb3/ g5#. Fritzie says that it is mate in 17, which usually denotes a massive material imbalance.

<30.Qxh7+ Bxh7 31.Rxh7+ Kf6 32.Rgg7> threatening g5# so... <32...Rxc7 33.dxc7 Qxc7 34.Rxd7>

click for larger view

<34...Qb8>

Black must keep control of d6 otherwise Rd6+ Kg5 Rh5#. White has R+B against Q but his position is probably winning : the black king is trapped

<35.Rhg7!> with the idea g5+ Ke6 Rge7#.

<35...Re8> to control e7

<36.g5+ Ke6 37.c4> and Bb3# is coming next.

Another defense is <35...Ke6> but <36.c4!> is very strong.

Black would probably consider the maneuver ... Nc5, ... Ne6 (or ... Nb7) to trade knights.

30 c5 ...

A quiet move and a little unusual as a response for a Thursday, but lets see what black has to be worried about. Well actually quite a lot! 31 Bb3+ is coming and if Nc7 is still there then black can quickly be forced to play Kg7 or Kg5 at which point Ne6+ wins Qd8!

30 ... Nf6 31 Bxg6 hxg6 32 Bb3+ Nd5 33 Qh7+ Kf6 34 g5+ Kxg5 35 Qh4#

30 ... bxc5 31 Bb3+ Kg7 (Kf6 32 Rxg6+ Kxg6 33 Qh6#) 32 Rxg6+ hxg6 (Kxg6 33 Qh6# or Kh8 33 Qxh7#) 33 Qh7+ Kf6 34 g5+ Kxg5 35 Qh4#

The king running is also flawed...

30 ... Kg8 31 Qxh7#
30 ... Kg7 31 Qxh7+ Kf6 Rxf6#

So black must take Nc7 to try to free up e8 as a flight square and relieve some of the pressure. Qxc7 is effectively resigning so...

30 ... Rxc7

31 Bb3+ Ke8 (Kf6 32 Rxg6+ Kxg6 33 Qh6# and Kg7 Qxh7#)

32 Rxg6 hxg6 (Qxh4 33 Re6+ winning)

Now there are lots of interesting possibilities Qh8! Qh6 but my favourite is...

33 Qh7 ...

Black must stop Qxg6+ mating

33 ... Qf6 34 dxc7 winning
33 ... Nf6 34 Qxg6+ ...

34 ... Kd7 35 Be6+ Kxe6 36 Qf5+ Kf7 37 Rh7+ Ke8 38 Qe6+ Qe7 (Re7 Rxe7+ Qxe7 Qxe7#) 39 Rxe7+ Kd8 40 dxc7# :-)

34 ... R8f7 35 Rh8+ (Kd7 Be6+ Kxe6 Qf5#) Ng8 36 Rxg8+ Kd7 37 Qe6#

34 ... Rcf7 35 Bxf7+ Rxf7 (Kd7 Qf5#) 36 Rh8+ Ng8 (Kd7 Qf5#) 37 Rxg8+ Kd7 38 Qxf7+ Kc8 (Qe7 Qxe7#) 39 Qc7#

So we probably continue with...

33 ... Rf6
34 Qh7 Nf8 (white is threatening Rh8!)
35 dxc7 Qd7
36 Qxf6 Qxc7
37 Rh8 Qe7
38 Qxc6+ Kd8
39 Qxb6+ black resigns...

<30.?>

Target: 3:30;000
Taken: 6:03;746, complex position but this is a bit TOO much

Material: White up, ♙

Candidates: pretty much <[Qxh7†]> all way, although Rxg6 and Rf5† came up to me a few times too.

-ML-
It is hard to consider that White is attacking with a pawn up, and Black's position is a mess. I can't see any compensation so how Black would win or draw even with a quiet move by White but if it can be ended right now White should go for it, obviously. The obvious starting sequence is to sac a Queen to bring another piece into the attack:

<30.Qxh7†! Bxh7 (30....Kf6 31.Rxg5‡ 1-0) 31.Rxh7† Kf6> all semi-forced thus far. However, now the key move arises.... the Rook on g5 is en prise, and after 32.Rf5†? Kg5 is at least drawing, because now the Rook on h7 is en prise, not savable with tempo. However, it should be noted that with support of the g5-Rook, the Black King is completely ensnared. Hey, why not just double up?

<32.Rhg7!> which is in fact a quiet move and as such the key move. Black is faced with 33.R5g6‡. Because the g6-Rook covers e6, Black cannot take the Knight because it would still be mate. There is only one move that protects the King from immediate mate.

<32....Qe8> which seems tricky. White has sacced a Queen for piece, and Black is doing the same now. Wait, is he?

<33.Nxe8† Ke6 (33....Rxe8 34.R5g6‡)> Black can't take back, so White is a piece up, but the White pieces are a little shaky now. Luckily for White, it will still be mate.

G Abrahams vs J H Beaty, 1962 (30.?)

White to play and win.

Material: Up a P. The Black Kf7 has 4 legal moves, although the White Rg5 x-rays g7 and g8. White has a battery Rh1 and Qh4, suggesting a sacrificial attack based on a local superiority near Kf7. The White Nc7 has a stable outpost and is available to join an attack on Kf7. The White Bc2 requires activation. The White Kc1 is secured from check.

Candidates (30.): Rxg6