Greek Gift sacrifice - Principles of Chess Middle Games

In the series of  Principles of Chess middle games, We have completed,
Weak Square & Outpost ( https://www.chess.com/blog/siddharth026/weak-square-outpost-principles-of-chess-middle-games )
Blockade & Restriction ( https://www.chess.com/blog/siddharth026/blockade-restriction-principles-of-chess-middle-games )
Opposite Side Castling ( https://www.chess.com/blog/siddharth026/opposite-side-castling-principles-of-chess-middle-games )
Today we are about to learn the most famous and most viewed trap. This line goes by the name, The Greek Gift Sacrifice. Here there is the temporary sacrifice of material for an overwhelming attack on the king or even a mate in many lines.

The Greek gift sacrifice is seen mostly in the "London system."

According to Wikipedia,

In chess, the Greek gift sacrifice, also known as the classical bishop sacrifice, is a typical sacrifice of a bishop by White playing Bxh7+ or Black playing Bxh2+ at some point after the opponent has castled kingside, with the goal generally being to attack and checkmate the opponent's king, or to regain material. It is important to consider the opponent's defences.

Greek Gift -

Greek gift generally looks something like this,

Now as you see, it involves the sacrifice of the bishop. It should be sure the plan should not backfire on you. To make sure a perfect Greek Gift exists in the position, Here is the point to be scrutinized.

In general, the attack will succeed if:

• The attacker has more control over the g5-square than the defender;
• The attacker's knight can move to g5 to deliver a check;
• The attacker's queen can join the attack, often on the h-file;
• The defender cannot move a piece to safely defend h7 square (or h2);
• The defender cannot easily reorganize his defence.
  

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To see how it works we will get down to our analysis board,
Here is our position,

Step 1 -
First, we ask ourselves, Are the general pieces ready for attack?
(General, here means knight, Bishop and queen.)
So, here they are developed.

Step 2 -
Do I have control over the g5 square if I sack my bishop?
Yes, Here we have control of it.

Step 3-
Is there anything stopping my queen from getting to h phile?
NO, My queen can go there after Ng5. 
( So I can sack my bishop here )
Note- Now I will play Move and then ask a question here since I know it's working and can calculate all lines. Not everyone is good at calculating all possibilities after a move. So let's play Bxh7.

Step 4 -
Calculate all the possible moves which the opponent can play now.
1-  kxh7
2- Kh8
Kh8 will lead into a winning position for white as black has to lose all kingside pieces.

If Kh8 ,

As you see, The opponent king is wide open, and we can develop easily and win against the lone king. We are up three pawns and an exchange.

Now you would say," Woah, how can I calculate that deep." Well, there is no need for it since this is an obvious move if you start identifying the threat. Also, this will happen only, If you face the stockfish or a person who is using stockfish.
People will generally fail much earlier. Here, I will show you multiple ways how,

Way 1 -

Way 2 -

Way 3 -

Way 4 -

If any of the variations have 4 ways of losing position for your opponent. You know this game is totally in your favour.

Now since we are talking about a Greek gift opponent will take the second option, Which is Kxh7.
Let's dive deeper into the steps.

Step 5- 
We bring our Knight into the attack by Ng5 as planned. 
Here King has 4 moves out of which three are blunders and one is the candidate move which is the most testing line.
Let's get the blunder out first since we should know all lines,
Kh8 ,

Kh6 ,

Kg8  ,

So, Now we go for the most testing line, which is Kg6
If Kg6,
We have two ideas 
Qg4 and h4.
Considering the situation, Either one of the moves will win you the game.
Now before testing, I will give you the hint. Generally in such a position f5 is best to move for black.
Now that you know this fact, Qg4 doesn't make sense since the f5 move will force us to move our queen back. Mind that the position is not losing but you sacked a piece. So you cant give the opponent a tempo here.

Now for some brilliant mind who will say Brother, we can do En passant here. Sorry, my friend, however good that move visually appeals to us, we can't play it here.

So we go with h4. Now we know f5 is the best attempt. So if he goes for f5, we ignore it and play h5. King has to h6. Here we lay our final blow Nxe6 discovers a check on the king and attacks the queen. In the end, we will be up a queen.

This is the most thematic way the Greek gift works.

As we know, Ideal lines are not generally seen in our games. I will give you multiple games to see and then we will solve puzzles on Greek gift sacrifices.

Match 1 - 

The opponent had to sacrifice his queen due to a greek gift.

Match 2-

When Greek gifter gets Greek gifted.

Match 3-

Failure of Greek Gift attempt.

We have seen a Greek gift sacrifice line. These are easy puzzles, and you have to answer my question.

1 - Make a move which marks Greek Gift,

2 - Make a move such that it creates attack by placing the piece on ideal square that we check while considering Greek Gift.

3 - Make a move that supports knight and create threat.

4 - What aggressive move will you play to create and attack.

5 - What was idea behind h4 move

I hope you love this blog on the Greek Gift sacrifice line. If you loved it you can also show support for my other blogs as listed in the box below.
Till then,
Let us all grow at chess together.

...The End...