The Ideas Behind The Move

In order to find the correct move, it is necessary to first find out the correct plan. There are 2 ways to formulate a plan.

a) Work forwards ie. if I play this, my opponent plays this and so on and evaluate.

A nicer common idea is to:

b) Work backwards. Find out if the current board position matches up to a previous pattern you've seen before and how to get the pieces to the correct squares. If no pattern emerges, ask yourself, how best to checkmate your opponent then find out the steps to make this happen.

White to play

Yes, it's another puzzle and this one I just played a moment ago. And this one is not too easy but not overly hard (if you know what to look for).

White is obviously in a great position. How does White further press home the advantage?

When you're ready for the solution, scroll down below......










(blanks deliberately placed)















The move is

1. b6!! Do you see the idea? Now in this game, Black felt forced to take on b6 and replied with 1.... cxb6 (shown below)



Now comes the entire idea behind the whole b-pawn push......

2. Rh7! (threatening mate on a7) and now 2.... Bxh7 is met with
3. Rd7 (and unavoidable mate)

Find The Continuation

I just finished off an online blitz game. I thought that I had played well until I ran it past Fritz..... and what a surprise I got!!!!

In the following puzzle, Black is under a huge pressure as below. Now we can all see what is coming. But that is not the question I want to ask. What I want to ask is:



Evaluate and find the best continuation after 1. Rxf5 gxf5 (this is what actually happened in the game).

When you have finished, see what Fritz found in the explanation far below! FYI, I didn't find the correct continuation but there's no stopping the silicon monster.






(Leaving blank spaces)











(Leaving more blank spaces)












1. Rxf5 gxf5 and we reach the position below. How do we proceed?



2. Ne4+!! A shot out of the blue!! Kh8 (forced) (2... Kh6 3. Qg5# naturally)

3. h6 (threatening 4. Qg7#)



and now.... Black is surprisingly mated.

2.... Rg8 is met by Qe5+ with unescapable mate to follow on g7

Puzzles With Imbalances

These are actual games I've played (don't scroll past the diagrams if you don't want to look at the solutions).

Game 1 - Winning Attack

Black (Me) has a winning attack, time to bring home the bacon....

(Black to play)


Game 2 - Find The Best Move

White had traded a Knight+Bishop for a Rook+Pawn to pry open my King position. I knew that Black has a slight advantage but I was thinking of how to best activate my pieces here. I sank into a deep long think.... and came up with a move. What move was it?
(Black to play) :


Game 3 - I Didn't See It Coming

My opponent thought that he could defend with Black and played 1.... Qd6. What did he miss?

(White to play)



Answers:

Game 1

1... Bf1+ 2. Rxf1 Rh2#

Game 2:


The move I played was 1.... Nh4! Suddenly the dawn of realisation came when my opponent realised that the Knight on h4 is untouchable. White tried 2. Qb3+ Bd5 and resigned a few moves later.

Added Question: Can you figure out why White cannot play 2. gxh4? Because it ends in mate!

1... Nh4
2. gxh4 Qxh2+
3. Kg1 Qh1+
4. Ke2 Qf3+
5. Kg1 e3!! and mate cannot be prevented

Game 3 -


The winning move was 1. f4! And mate cannot be stopped as the the next move is Qh7#. If
1. f4 Nxf4 (else 1.... Rh8 2. f7=Q+ Bxf8 3. Qg5#)
2. Rxf4 also results in mate after Qh7+ and Qh4#

Automatic Moves

We've all done it from time to time, we make automatic moves on what we think are forced moves.

This is a game I had just a few minutes ago. When I ran it through Fritz, imagine my surprise.

White had recaptured the pawn on c4 with 22. dxc4. What should Black play?

22.... Nxb4 looks nice. Winning a pawn and gaining a tempo due to the discovered attack on White's queen.

Can you find a better plan?

Be warned, the calculation of the correct line is not easy as there are 2 important variations you have to consider that runs up till 6 ply deep. Remember tactics predominate nearly everything in chess.

Now what if I were to tell you there is a way to win at least a piece?

That got your interest hasn't it?

If you need to, stop now before looking at the answer below:

Ready? The winning move.

22.... Nd4!!
The White Queen is forced to move and there are 2 important variations:

Let's take a) 23. Qd1 or any other Queen move except 23. Qe3 - I'll explain later

Now comes the shocker 23....e5!!


a1) If the bishop moves away say 24. Bd2, then 24... Qh3 is decisive threatening mate on g2.
25. f3 (forced) Qxg3+
26. Kh1 Nxf3 and Black's attack crashes through and White must give up material to stave off mate.

a2) If the bishop takes with 24. Bxe5 then 24... Nf3+
25. Kg2 Nxe5+ wins the bishop

Now we go back to the other continuation
b) 23. Qe3 now e5 doesn't work but....


23... g5!! is a killer

Obviously the pawn cannot be taken as 24. hxg5 hxg5 with mate on Rh1#

24. Bxg5 is no solution because of Knight fork after 24.... hxg5 with 25... Nf3+ to follow.

That just leaves

24. Be5 Nf3+
25. Kg2 Nxe5+ winning the bishop

For all purposes, there is a stronger move in the earlier variation but given the practicalities of play, winning the bishop is fairly decisive.

Find The Next Move

In this game, my opponent, Black just played 1.... exf4.

How would you evaluate this position? White with a slight advantage? Equal?

How should White continue?

Hint: The continuation is not easy to see but you know that when the Knight+Queen is about, there's always tactical shots waiting. Think about it for at least 5 minutes.

Answers can be found by highlighting between the brackets

[2. ... e5!! and Black must lose a piece. The threat is no matter what Black does to take the pawn, the followup is 3. Ne7+! as the Knight is immune to capture due to potential mate on h7. The Black King can escape via g6 but the attack for White by then is utterly crushing with 4. Qxh7 and 5. Nf6.]

Tactics Exercise

This puzzle is a tough one. It is - if you don't see the idea or continuing line. But once you see it, you'll understand it.

This just occurred less than 10 min ago in a blitz game I played online.

I am Black. White is in absolute dire straits but Black must play carefully.

White had his King run up the board to h4 to escape the pin of his Knight on f3.

I did not see the following line unfortunately and missed the opportunity to end this in the most efficient manner.

Black to play and mate (Hint: in less than 5).

Answer can be found by highlighting the brackets
[1... Ng6+

2. Kh5 Qg4 and White cannot stop Nf4# or Qh4#

2. Kh3 Bd6! and White cannot stop Qh2# or Qg3#]

Tactics Puzzle

Here's an interesting position I just played on FICS.

Hint: Black to move and win material.

Answer can be found by highlighting between the brackets
[1. Bxe4 Bxe4
2. Nxe4 Qxe4
3. Re8 Qf3
4. Rxe3! and White cannot take the Rook back because of Bd4 pinning the Queen]

Forced Recaptures

This game was played a couple of days ago and I admit it's not easy to see the idea behind it.

I am White.

I am down a whole Rook for 2 connected passed pawns on the g-file and h-file and now Black had just played 1.... Nxf2 forking my Rook and Bishop.

It's definitely not easy to spot this but I had actually planned it to tempt the Knight to play Nxf2 (a juicy fork is always tempting especially when you're a piece ahead).

And this time Black fell into a very nasty trap I laid for him.

Can you see White's response?

If you want to puzzle this over before looking at the answer (with diagram), please do stop here now.

White to play and win.

------------- Answer ------------

Have you seen my idea? If you haven't, don't worry. Ready?

The idea is to play

2. Bg2!!

If the Knight does not capture the Rook nor block the h-pawn (I'll give the continuation after 2.... Rh8 later) then

3. h8=Q Rxh8
4. Rxh8+ followed by
5. g8=Q gives me a new Queen

So Black played

2... Nxh1

And now comes the shocker

3. Bxb7! (see 2nd diagram)

and now it's game over.

If 3... Kxb7
4. g7 and one of my connected pawns will be traded for the Rook and the other pawn will Queen easily.

If 3... Rh8
4. Bxh1 with Be4 to follow and then g7 and there's no stopping any of the pawns to queen and the Rook will still be lost in the process.

Oh if 2.... Rh8 then I would win transpose into the lines mentioned above after 3. Bxb7 and either .... Nxh1 4. Bxh1 or ... Kxb7 4. g7

Black chose the continuation after 3... Rh8 and resigned a few moves later.

This brings to mind an important rule: You are not always forced to recapture a piece that has just been captured. Always be on the lookout for tactics and combinations.

PS: I'll be away on holiday for the next couple of weeks, so till then, cheerios, everyone and take care.

Calculating Forcing Moves

GM Larry Christiansen (of ICC's Attack With LarryC column) is a renowned fierce attacker.

Here's what he once said about tactics and combinations.

He quotes,"One extremely important point I wish to emphasize is to always look at forcing moves.... As a player, I tended to calculate fairly deeply but I would often abandon a tactical possibility just when it seemed to lose its feel."

What Larry Christiansen means is that when you're about to embark on a dangerous combination, you should always try to calculate it to its very end.

Here's a game I played recently on FICS.

White in order to get over the misfortune, tried to castle his king into safety with the move 13. O-O and of course, this meant that this move was a case of out of the frying pan and into the fire.

It's Black to play.

a. Can you calculate how to take advantage of this situation?
b. How far did you calculate? Where did you stop?
c. What are White's responses to your possible moves?

In this case here, I calculated the above to its natural conclusion. So if you feel like giving this a go, Please stop reading now if you want to work this out for yourself.

----------- Answer below ---------------

I'm sure most of you would have found the immediate move
13.... Nxe3
14. fxe3 Qxe3+

Now here's the trick. What are White's responses?

A quick calculation reveals that
15. Kh1 loses a piece after
15.... Qxe2
16. Qxe2 Bxe2 so this line can be quickly discarded by White since Black will win.

But are there any possible responses?

15. Rf2 was the only other option.

Okay, the Rook defends e2 and blocks the check. The phrase "blocks the check" should now stir something in your head.

How do you make use of this pin?

15... Bc5! is the killer move. The rook is only defended once by the King so putting additional pressure on the pin makes sense.

Can White defend it? The only move left is:

16. Qe1 (White Queen has to defend the d2 Knight, e2 Knight and f2 Rook) (See 2nd diagram on right)

If you've calculated this far, can you now apply the correct combination?

16.... Bxe2 and now it's over. The rest of the game as follows and this is what happened:
17. c4 (White is paralyzsed as any other moves does not affect the outcome) Qxf2+
18. Qxf2 Bxf2+
19. Kxf2 Bh5 winning with a whole Rook up
White resigns

Surprising, all these moves are forced. And if you found this line (like I did), it's kind of amazing that you had actually calculated some 12 ply moves in all.

Another Tactical Puzzle

Have a look at this position.

Black has come under enormous pressure and played Nf7 in desperation.

Find White's best move.

White to play and win.

Answers can be found by highlighting the brackets.

Answer [
1. Rxh8+ Nxh8
2. Qxd6!! Qxd6
3. e7 and

Black must have give up the Black Queen else
4. e8=Q+ loses either the Knight after
5. Qxh8 or the Black Queen as
4.... Kc7 loses to the Knight fork with b5+]

Simple Tactical Puzzle

I recently had a very wild game in the French Winawer (I was White).

I reached this position as shown (see picture on left).

White is clearly winning.

Black's Rook is there for the taking and taking the Rook with check is always a plus.

The idea behind this small exercise is to be able to see moves whilst moving the pieces in your head.

Now calculate the lines after 1. Bxf8+

Question 1: Can you see the mating position after 1.... Kxf8?

Answer can be found by highlighting between the brackets.

Answer:
[ 1.... Kxf8 2. Qe7+ Kg8 3. Rd8 and mate follows]

We now know that Black should take back with the Queen.

So 1. Bxf8+ Qxf8 is pretty much forced.

For your convenience, I've attached the 2nd picture for this line. But you can still work it out in your head should you choose not to use the 2nd picture.

Question 2: Find a way to win/finish off Black.

Answer :
[2. Rxc6!

If 2... bxc6 3. Rd7+ Kg8 4. Rd8 wins the Black Queen. Note that 3... Kh6 is not possible because of Qg5#

If 2....Nf6
3. Rxf6! Qxf6
4. Rd7+ nabs the Black Queen

If Black makes any other move,
3. Rcd6 and Black is still going to lose the Black Queen because Rd7+ is coming]

Ghosts And Fallability

While playing games be it, OTB or over the internet, I noticed a few 'ghosts' cropping up in my gameplay.

One of these flaws was that I have a tendency to not play the best moves after getting in a few nice moves. In other words, after making a series of good moves, I followed it up with an impulsive move which usually leads to the start of my downfall.

I will highlight this in this game here (see 1st diagram).

White has a slight edge here having a passed pawn and more active pieces. With correct play, White should be able to convert this.

But I was disturbed by the doubling of the Rooks on the h-file. I definitely do not want Black to play Bxf3 leading to a doubling of my pawn structure and even worse, allowing Black to crash through the Kingside which has become porous (with 1... Bxf3 2. gxf3 Rxh3) - my Queen had gone on a temporary excursion to wipe Black's a pawn off the board - hence the awkward position.

I looked first at 1. Re3. Not bad, this protects the Knight and indirectly the h3 pawn as well. It also provides some cover for my King should it decide to go to the e-file.

Then.... I looked at 1. Rxe4, sacrificing an exchange with Rook for Bishop and pawn after 1. Rxe4 dxe4 2. Qxe4. The more I looked at it, the better it seemed. First, I had broken up Black's pawn control of the center. The Knight is excellently posted on f3, protecting all the necessary squares of h4, g5 and e5. The Queen on e4 stops all tricks of Black pushing the g-pawn.

So the exchange sacrifice went ahead.

1. Rxe4 dxe4
2. Qxe4 Re8 (see 2nd diagram)

Hmmmm.... what now? Black realises that there is no way through on the h-file but decides to plant his Rook on e8 (?).

I half expected Black to contest the d-file with 2... Rd8 instead after which 3. Re1 (wisely avoiding the trade but having to give up the d-file). At some point Black cannot wait to trade off the Queens so that Black's Rook can be dominant.

I needed temporary control of the d-file but I needed to do something better. So I hitched upon a move that encompasses 2 different ideas.

So I played 3. Qg4 (see 3rd diagram)

Attacks the undefended Rook but more importantly, it allows my Rook to invade the 7th rank at d7 and attack the c-pawn and the Black Queen - a double attack and the c-pawn will fall.

3.... Rh6
4. h4! Rb6
5. b3 Ra8 (see 4th diagram)

In this position, I played

6. hxg5.

A mistake. See? Mistakes are now starting to creep into my play. I was concerned with

6. Nxg5 Rg6 (a Rook pin)

It is so unnatural to allow a pin unto yourself and I thought it was an uncomfortable pin that might cause me problems later. However, I failed to see that

7. Rd7 any Black Queen move
8. h5! and e6! are very strong replies and there was nothing to be afraid of.

6.... Rxa2
7. Rd7 Qe8
8. g3 (forced) Re6
9. Rxc7 Qd8? (see 5th diagram)

I had a chance to clarify things with 10. Qxe6! Qxc7 11. Qh6+ and achieve a winning endgame with such a pawn majority.

And now my ghosts are starting to haunt me.

10. Rxc5?? (see last diagram) A blunder of humongous proportions!

What I saw was that Black didn't seem to have anything after 10.... Qd3+ but there was something critical I missed.

Can you see how Black can win in this position?

My opponent didn't see it either and lost in a few moves later.

Answer can be found by highlighting between the brackets.
[ 10. .... Qd3+ 11. Kg2 Qe3!! and the White Rook on c5 is lost 12. Qd4 does not work because of Rxf2+ and the Knight is lost and the Queens are coming off in the next move.]

Calculating Sacrifices

My opponent and I reached this unusual middlegame from the Classical Sicilian. Black's King is left all alone. And this usually signifies an attack. Black had just played Bb7 (see 1st diagram). So it is White to move.

Do you know what I was thinking?

1. Bxf7! was the sacrifice to open up the area around the Black King.

The question is: Do you think the sacrifice 1. Bxf7 works?

Calculate the lines after 1.... Kxf7.

Once you're ready, I'll go into the following thought processes that goes into my dysfunctional brain.

So please bear with me. :)

First of all, why 1. Bxf7? White has a positional advantage in that it has more active pieces and the pieces control a lot of squares on the board. True, I can play the slow way of squeezing my opponent to death with moves likes 1. a4, even h4 to break up the Black pawns and cramped Black further in.

Why sacrifice unnecessarily?

I believe that for a patzer player like myself, it is important to learn to see tactics and combinations where they occur. Rather than being afraid of playing bold moves, one should actively seek out good moves because that is the way a player can improve.

Anyway, back to the subject.

Does 1. Bxf7 work? Let's work it out.

What can Black reply with?

Looking at this, I calculated a few replies by Black. But I'll just explain one for the sake of brevity.

1..... Kxf7 is the natural response

2. Ng5+ (the natural followup, bringing another piece into the attack) Kg8 ( 2.... Kg7 or Kf8 runs into the horrible twin fork between King and Queen with Ne6+)
3. Ne6 (stifling the e7-pawn, effectively cutting off communication between Black Queen and King - see 2nd picture) Qd7 (forced)
4. Qd4 (Black is now forced to give up his Queen to prevent mate on g7)

Sweet.

I have actually calculated other lines as well including the replies
1 .... Rf8, 1.... Bxe4 but that discussion will take far too long for this post.

Instead, I'll leave you with a final puzzle after

1.... Rf8
2. Ng5 Bc8
3. Bd5 Nc6
4. Bxc6 (see 3rd diagram)

Now what happens if Black plays 4.... Qxc6?

Can you spot the mating pattern by White? Answers can be found by highlighting between the brackets. :)

[5. Rxe7+ leads to

..... 5. Kg8 leads to 6. Qc3 and mate on next move with 7. Qg7#
..... 5. Kh6 6. Rxh7#
..... 5. Kh8 6. Qd3+ Kg8 7. Qg7#
..... 5. Kf6 6. Rae1 and Black is going to be mated in the next few moves unable to stop mating threats with say Qd4+/Qf4+/Nh7+.]

Find The Best Move

I was having a mini-training session with Fritz (set to a much much lower performance setting naturally). It's been a very very tough fight to bring home the point.

And we arrived at the following interesting position (see inset). White has a slight advantage in the position.

I am White and it is White's turn to move.

Let us evaluate this:

What are Black's threats?

Black threatens to liberate his Knight's position with 1... Nb6 (putting pressure on the d5 pawn) or 1.. Nc5/Nf6 (forming a double battery and also putting pressure on the d5 pawn) afterwhich, Black threatens to take the h2-pawn with 2... Qxh2.

The question is: How can White stop this and yet maintain the advantage?

The answer can be found by highlighting between the brackets
[White has the brilliant resource 1. Bd4!! which stops this nonsense. Now the Black Knight is pinned to its position because if 1... Nf6 2. Qa7# and 1.... Nc5 or Nb6 2. Be5 wins the Queen]

Tactical Puzzle

Here's a very neat little tactical shot.

Black has just played 21.... Qxh4.

White to play and get an advantage.

Answers as usual can be shown by highlighting between the brackets

[The famous Knight moves strikes again.
22. Nxg7+ Kf7
23. Qxe7+! Kxe7
24. Nxf5+ Kd7
25. Nxh4 and White is a minor piece up and winning.]

A Great Game

Tonight, I played a great game. As a result, I will show you the game in its entirety. I am Black.

1. f4 Nf6 2. Nf3 b6 3. e3 Bb7 4. d4 e6 5. Bd3 g6 6. O-O Bg7 7. c4 d6 8. Nc3 O-O 9. e4 a6 10. Re1 Nbd7 11. h3 c5 12. d5 Nh5 13. g4 Nhf6 14. Kh2 (see 1st diagram)

I am very proud of the next move. I sank into a very long thought here. Guess what move did I play in the end? And this candidate move was not easy to see but easy to calculate.

The answer can be shown by highlighting between the brackets.

[14.... Re8!! (that's right I blocked my f6 Knight's only escape route to entice the e-pawn forward, I know what you're thinking... wth?!) ]

Now watch the drama unfold.....

15. e5 dxe5 (now all the moves are forced and I had calculated all of this beforehand)
16. fxe5 exd5
17. exf6 Rxe1
18. Qxe1 Qxf6

Here my opponent slipped up. He played

19. Ng5? Ne5
20. Qg3 (see 2nd diagram on right)

And now, it is my turn to slip up. I played

20... Re8

However, there is a stronger move.

20. .... Nxd3! And the Knight surprisingly cannot be taken by the White Queen. ie. White cannot play 21. Qxd3. Can you figure out why?

The answer can be shown by highlighting between the brackets.

[That's because this leads to a discovered attack 21. Qxd3 Qf2+ 22. Kh1 dxc4+ and the White Queen is lost]

21. Nxd5 Bxd5
22. cxd5 (see 3rd diagram on right)

and now the final nail in the coffin....

22... Nxd3
23. Qxd3?? hastens the end although other alternatives are just as bad as 23. Bd2 Re2+ wins the bishop with a crushing attack to boot.
23... Qf2+
24. Kh1 Re1+
25. Qf1 Rxf1#
0-1

A terrific finish. My opponent was gracious enough to allow me to go onto checkmate.

I checked my analysis with Fritz and barring the slip on move 20. The 14th move was the best way to equalise in that position.

Tactics Puzzles

I'm taking a slight breather from my studies for my finals exam.

Here are 3 tactical puzzles for your enjoyment!

Answers can be found by highlighting between the brackets.

Puzzle 1.

White's Knight is forced to retreat, how should Black make use of this to get an advantage?

[Black wins a piece 1.... Bxa3 If 2. bxa3 Ba4 leaves Black up the exchange with Rook for Knight]





Puzzle 2.

Black just played 1.... Kf5, how can White win?

[White's c-pawn Queens after 1. Rb5! Rxb5 2. c8Q+ and wherever the Black King goes, 3. Qe8+ nabs the Black Rook]










Puzzle 3.

Black just played 1.... Kf8 to escape the Queen check, how should White follow up and give checkmate?

[1. Nd6! Qf6 or Qa2 (forced else 2. Qf7#) 2. Qe8+ Rxe8 3. Rxe8#]

Checkmate Puzzle

White is of course, completely winning in the puzzle shown.

The question is:

Can you find the fastest way to checkmate the Black King? White to play.

Answer can be found by highlighting between the brackets
[I got a mate in 3 moves with
1. Qf5+ Ke8
2. Nd6+ Kd8
3. Nd5#

But there's actually a mate in 2 moves! The exact continuation is
1. Qe6!!
If ....Ra6 or Rh6 or g6 2. Qg8#
Any other Black moves, 2. Ng6#]

Where's The Tactics?

Tactics can occur in the unlikeliest of places sometimes. Take for instance, the following game I played recently at Ryde-Eastwood League club. I only found out after going over my game with Fritz and Fritz instantly spewed out the tactical shot!

Rather than give you the position and give you a hint, what I intend to do separately here is to show a consecutive sequence of 5 moves that are being played out.

The idea is to mimic an actual game scenario - which it is. Here, no one is going to give you the exact position and say, "White to play and win" or "Black to mate in 3 moves" or something obvious.

No, I am not going to give you any hints at all other than the fact that this is DEFINITELY NOT EASY to see over the board.

So set yourself a time control of at least 20 minutes for the whole of this exercise. If possible, set up the actual board and pieces according to the first diagram shown. Examine each sequence of moves in turn (take your time), when you think you have seen enough and cannot find any good moves, go to the next position. Then think over the position again. The idea is NOT to go backwards. Once you have moved forward each position, do not go back. This is to provide impetus for you to analyse and mimic the conditions exactly similar to an actual game in progress.

Remember: Do NOT RUSH! Take as much time as you like for each position.

Without further ado, let's go onto the 1st position!

FEN position
4k2r/ppq2pp1/2r1p2p/3pPn2/Pb1P1B2/1P6/R3KPPP/1N1Q1R2 b k - 0 19

19. Rf1
Black to play and move
Examine this position carefully,
if you're happy that there are no tactics available here,
please move on to the next position

19. ... O-O

20. f3
Black to play and move
Examine this position carefully,
if you're happy that there are no tactics available here,
please move on to the next position.
Do NOT go back to the previous position.

20. ... Qb6
21. Be3
Black to play and move
Examine this position carefully,
if you're happy that there are no tactics available here,
please move on to the next position.
Do NOT go back to the previous position.

21. ... Rfc8
22. g4
Black to play and move
Examine this position carefully,
if you're happy that there are no tactics available here,
please move on to the next position.
Do NOT go back to the previous position.

22. ... Nxe3
23. Kxe3
Black to play and move
Examine this position carefully.

This is the last position.

Now, have you seen the tactic that was immersed in one of these positions?

One of the above diagrams contains a very deep tactic, one that is not easy to spot. If you cannot find it, don't fret. I didn't see it either.

To see the answer, please highlight between the brackets.

[The very deep tactic occurred on move 22. g4 for Black above - the 2nd last diagram. The amazing tactic goes as follows:

22... Qa6+!
23. Kf2 (Note: White is worse after ....
23.Qd3 Rc2+
24.Rxc2 Rxc2+
25.Bd2 Nxd4+
26.Ke3 (26.Kg3 Bxd2 27.Nxd2 Qd3 28.Rf2 Nxb3 and White loses a piece)
26.... Qb6
27.Kf2 (if 27. Qxd4 Bxd2+ 28. Nxd2 Rc3+ and the White Queen is lost)
27.... Bxd2
28.Nxd2 Nxb3+
29.Kg3 Nxd2 )
23... Rc2+! An amazing sacrifice, you say.... watch what follows now
24. Rxc2 Rxc2+!
25. Qxc2 Qxf1+!! An incredible temporary Queen sac - did you see it?
26. Kxf1 Nxe3+
27. Ke2 Nxc2
Now Black gets back all his material and is a piece up and winning. Incredible.
]