"SCAN"
The first process is called SCAN. As we SCAN the board, we will be looking for key points to remember. These points will help lead us to a move decision. Each letter of the word SCAN stands for certain key features of the game at hand. The easiest way to learn SCAN is by example, so let's take a look at the following position (diagram 1):
Diagram 1
It's White's turn to move in this position (at move 25) and I had to come up with a good move as Black's pressure is starting to build on the e-file and my pawn at e6 is about to drop.
The first letter of SCAN stands for "S - Save the King." The first piece of information you need to know is the relative safety of both kings. Is your king's position safe? Is your opponent's king safe from attack? Looking at the position, we see that White's king is castled and still has his defending pawns intact on their original squares. White also has both rooks guarding the back rank. I wasn't too thrilled that my rooks were on guard duty, but that's life. Also, when I do the SCAN analysis during a correspondence chess game I have the luxury of using color to mark squares, so break out the crayons. Color in White's castled position with green (diagram 2).
Diagram 2
Diagram 3
Next, we look at Black's king. His king was castled also, but some tragic events have occurred in past moves. Black's king has been moved into the corner (and is trapped on h8) and one of the protecting pawns (f7) has been removed. Black's king cannot be considered safe and the first point to remember is that White could be looking for a direct attack on the remaining structure. Mark Black's king and the two pawns on h7 and g6 with yellow (diagram 3).
The second letter stands for "C - Control the Center." Which side is controlling the center squares and the attacking routes? White has no center pawns, so the only thing we can consider are the lines of attack of each of White's pieces. Draw those in with red lines (diagram 4). As can be seen, White's center control amounts to a single square (e4).
Diagram 4
Diagram 5
The queen on h4 has control over the 4th rank (but so what?), and the e1 rook has minimal control over the e-file as Black's doubled rooks will prevail. With only this rook protecting the pawn on e6, the pawn will drop on the next move. White's only piece of the bunch that has any influence is the bishop on c2, which is attacking the pawn on g6. More on this bishop in the next part of this analysis. What does Black control? We mark all the squares influenced by Black's pawns and pieces (diagram 5). Black's pawns are in control of c4, d4 and e4 and Black's bishop cuts along the b2-g7 diagonal, controlling e5. The attack on the b2 pawn will be handled in the next part of the analysis. We can conclude that Black's control over the center is better than White's at this time.
The third letter stands for "A - Analyze the Piece Positions" and has two parts. The first is:
1) What to Attack
White needs to know which Black pieces are up for grabs. We begin with A) Unprotected pieces. Are there any pieces in Black's camp that are completely unprotected? In this case, only Black's queen is unprotected, but it is unreachable. This means that if White chooses to capture something, it will typically cost him material. In many games, your opponent will have pieces that are unprotected. I always mark these in red. You may not be able to capture any of these "marked" pieces, but you need to be aware that they exist. Never overlook a free piece. For example (diagram 6), illustrates the position back at move 7 in this same game, and we can see that Black's b7 bishop is unprotected.
Diagram 6
Diagram 7
At that time, White could not capture either of these pieces, but seeing what's available for capture is an important part of the process. Back to our current position (diagram 7). Since there is nothing "free" for the taking, we next look at B) Pieces with only one defender. Again, limited choices, but there are some (diagram 8). The e7 rook is only protected by it's partner on e8, and the pawns marked in yellow are
Diagram 8
Diagram 9
possible targets. It's obvious that we can't trade White's queen for Black's e7 rook. If we overlay this diagram with Diagram 4, we see that our only possible attack is on the pawn at g6 (Diagram 9). This would technically be trading down material and it must be considered very carefully before being executed. I know it's romantic to sacrifice a piece in order to win a game, but never give up material unless you are sure about it. We will keep the move 25.Bxg6 in mind and see if it really is a sacrifice of material.
Continuing on, we come to C) Key pawns. We must look at Black's overall pawn structure to see if there are any weaknesses. We are looking for:
1) Isolated pawns. An isolated pawn is one that has no supporting pawns on either side. Since it has to be protected by pieces, your opponent will have a difficult time hanging on to it.
2) Pawn chains. By attacking the base or middle pawn in your opponent’s chain of pawns, you create an isolated pawn situation. This weakens one or a whole string of pawns for later attack.3) Pawns in front of a castled King. Opening a hole to your opponent's King will give you an attacking line to make use of with your other pieces.
Under "3" we find that the g6 and h7 pawns are weak and could be attacked. If White were to play 25.Bxg6, Black would be under considerable pressure if he recaptured with the h7 pawn (diagram 10).
Diagram 10
Diagram 11
White's queen and knight are prepared to wipe up several of Black's pieces, so the recapture of the bishop with ...hxg6 is out. Black will have to deal with the loss of material and would then be faced with the attack on his e8 rook (diagram 11). The e8 rook cannot move as either 25...Rd8? 26.Qxe7 or 25...Rf8?? 26.Nf7+ with mate next move. Thus, the e8 rook is lost to capture by White's bishop. Works for me. The move 25.Bxg6 is therefore not a sacrifice of material and is high on the list of possible moves.
There will be times when further analysis must be done and there are two further categories I'd like to mention:
D) Squares on open files or diagonals. Prevent your opponent from putting a piece on the target square. This is the idea of attacking "space."
E) The opponent's King. If you have the opportunity, checkmate the opponent's King. The basic idea for checkmating the king is "Trap and Mate." We do this by driving the king to the edge of the board and trapping him there. One final check will end the game.
Note that we have this last condition already on the board. Black's king is currently pinned down to the h8 square and the method suggests that we should be looking for a move which will finish off the Black king. More support for the move 25.Bxg6.
There is one last thing we need to do to complete the piece analysis. We need to look at:
2) How to Defend a Piece
What good would it do us to play a move, only to lose a major piece or get mated in the process? Always look at the opponent's threats before committing to any move. What is Black threatening to capture or do next? Ask yourself, "If it was the opponent's move in hand, what would he do next?" Looking at the position (diagram 12), Black can capture the e6 pawn using either a rook or a bishop and he can capture the pawn on b2 with the bishop on g7.
Diagram 12
Against these threats we need to ask the following questions:
A) Is the threat real? Take a good look at the situation. Does your opponent really want to capture your piece or is he hoping that you will move it out of his way? Look beyond the threat to see what he has in mind.Here, both threats are real as Black could capture either pawn and get away with it.
B) Does it matter? Is his threat of any concern to you at all? If you are going to checkmate him on the next move no matter what happens, then the threat does not matter. If you ignore the threat and you lose a major piece, or worse (checkmated), then the threat is real and it matters very much.
In this case, the attacking threat of White's 25.Bxg6 is greater than Black's threat to capture either pawn. The threat of Black's captures does not matter as White can win material. If any of Black's threats had mattered at all then you would need to follow the next step:
C) Decide. Once you know if the threat is real and if it matters then you have three choices:
- Remove the threat. Capture the attacking piece.
- Counter attack. Threaten to capture another piece of equal or greater value in return.
- Protect the piece. If this is an even trade fine, but if you would be down the exchange with no other compensation, then protecting the piece further would make no sense.
- Run. Move the piece or lose it.
The last letter in SCAN is "N - Next Move," in which we should look at possible candidate moves.
Already we have a good move in hand with 25.Bxg6, but are there any others? Faced with the loss of material if White doesn't play 25.Bxg6, the choices are zip. The only good move here is 25.Bxg6. Before playing this move, White only needs to calculate a few variations to see what comes next: 25.Bxg6 Rxe6 (recovering the pawn at least) 26.Bxe8 and now...
1) 26...Qxe8 27.Rxe6 Bxe6 28.Re1 Bxb2 29.Qg4 Bxg4 30.Rxe8+ Kg7 31.Nxg4 and White is winning.
2) 26...Rxe8 (the actual game continuation) 27.Nf7+ Kg8 28.Rxe8+ Qxe8 29.Nd6 and White can pick up material with the better position.
Conclusion
White's best move is 25.Bxg6 and the resulting line that follows it. Most of your moves will not be this dramatic and finding the correct move in certain situations might need a bit more analysis. The process is simple though (it takes longer to describe it than to actually do it), and I'm sure that once you get the knack of it, your analysis will take only a few minutes to do at the board.SCAN
S = Save the King. The first thing to do before making any move is to ask the question, "Is my King safe from attack?" Your king must be kept safe at all costs.
C = Control the Center. Control of the center is a critical element of the game of chess. If you do not secure this territory, you will not be able to move your pieces effectively and you cannot prevent the opponent from invading your position. Also, do a count of all the squares on the opponent’s side of the board that you can influence with your pieces and pawns.
A = Analyze the Piece Positions. You need to know what you can attack and what you need to defend:
1) What to Attack:
A) Unprotected pieces. Any piece (Queen, Rook, Bishop or Knight), that has no defenders is an unprotected piece.
B) Pieces with only one defender. These pieces are poorly protected. If the defender is drawn away then the main target piece is now up for grabs.
C) Key pawns. The opponent's pawn structure should be compromised whenever possible.
- Isolated pawns. An isolated pawn is one that has no supporting pawns on either side. Since it has to be protected by pieces, your opponent will have a difficult time hanging on to it.
- Pawn chains. By attacking the base or middle pawn in your opponent’s chain of pawns, you create an isolated pawn situation. This weakens one or a whole string of pawns for later attack.
- Pawns in front of a castled King. Opening a hole to your opponent's King will give you an attacking line to make use of with your other pieces.
E) The opponent's King. If you have the opportunity, checkmate the opponent's King. The basic idea for checkmating the king is "Trap and Mate." We do this by driving the king to the edge of the board and trapping him there. One final check will end the game.
2) How to Defend a Piece:
A) Is the threat real? Take a good look at the situation. Does your opponent really want to capture your piece or is he hoping that you will move it out of his way? Look beyond the threat to see what he has in mind.
B) Does it matter? Is his threat of any concern to you at all? If you are going to checkmate him on the next move no matter what happens, then the threat does not matter. If you ignore the threat and you lose a major piece, or worse(checkmated), then the threat is real and it matters very much.
C) Decide. Once you know if the threat is real and if it matters then you have three choices:
- Remove the threat. Capture the attacking piece.
- Counter attack. Threaten to capture another piece of equal or greater value in return.
- Protect the piece. If this is an even trade fine, but if you would be down the exchange with no other compensation, then protecting the piece further would make no sense.
- Run. Move the piece or lose it.
N = Next Move(s). Unless you are faced with a "must play" move (recapture, answering a check, etc.), make a list of the candidate moves that fulfill the requirements of the analysis and then choose the move that you find best in the situation.