Piece Functions

In earlier posts (here, and here) I described a new approach I am taking to teaching chess to my son using the concept of the Three Levels of Vision:

Three Levels of Vision

1. Bottom-up perception.  See the individual piece AND the squares it can move to as one inseparable unit.  See the lines of power (like an aura) emanating from the piece.
2. Top-down processing.  See the six functional relationships between the pieces.
3. Interconnected system.  See the entire board as (5 to 6) groups of pieces with functional relationships (not unconnected sets of individual pieces).

To understand the first level of vision you only need one piece.  There are simple exercises and activities to build this vision.

But the second level requires a second piece (allied or enemy) to understand any of the functions, and requires a third piece to understand all six functions.

The Six Piece Interactions (or "connections")

1. Allied pieces:  (1) defend, (2) limit, and (3) shielding.
2. Enemy pieces:  (4) attack, (5) blockade, and (6) restrict.

Writing this blog I realized that this list is incorrect.  Read to the bottom for an updated list!

Let's look at what happens when two allied pieces are on the board:

Here we see the queen "connects" with his allied bishop using the (1) defend function.  But that is not the only interaction taking place here:

No good deed goes unpunished!  The queen is providing a useful function by defending his allied bishop, but the bishop is not being so helpful and interacts with his allied queen using the (2) limit function.  The limit function is harder for beginners to see because the bishop is not visually "connecting" with the queen...the queen is "connecting" with the bishop.  

The same relationship between functions is true with one enemy and one allied piece:

Here we see the queen "connects" with the enemy bishop using the (4) attack function.  But, again, that is not the only interaction taking place.

The bishop also interacts with the enemy queen using the (5) blockade function.  Like the (2) limit function, the blockade function is harder for beginners to see because the bishop is not actually "connecting" with the queen...the queen is "connecting" with the bishop.  

This gives us TWO pairs of (almost) inseparable functions:

1. Allied pieces:  (1) defend PLUS (2) limit
2. Enemy pieces:  (4) attack PLUS (5) blockade

"Almost" because these pairs apply to all chess pieces except for the pawn, king, and knight.  

The pawn does not move and capture in the same direction, which means the pawn can both (1) defend without being (2) limited, and can (4) attack without being (5) blockaded.  

The first pair applies to the king and knight, but to a lesser extent due to their more limited scope of movement.  Since they are short range pieces the impact of being (2) limited is only the one square the allied piece is standing on but not the squares behind it.  (Note -- long range pieces are prevented from moving to squares BEHIND the defend piece AND the square the defended/allied piece is standing on.)

The second pair does NOT apply to the king or the knight.  When a king is attacking an enemy piece, he can move to that square (by capturing) UNLESS the enemy piece is defended which means that square is (6) restricted.  When a knight is attacking an enemy piece, he is not in turn prevented from moving to that square (by capturing).  (Note -- unlike the knight, long range pieces are prevented from moving to squares BEHIND the attacked piece but, like the knight, not the square the attacked piece is standing on.)

What happens when three pieces are on the board (two allied pieces and one enemy piece), but not in a line?

Here we have the same TWO PAIRS discussed above:  between the allied queen and bishop (defend plus limit), and between the enemy queen and bishop (attack plus blockade).

It is important to note in this position that the bishop is NOT performing the additional (3) shield function because the pieces are not in a line.  

Now the queens are on the same line with the bishop standing between them.  

The (3) shield function is more complicated than the two basic pairs, and at least one of the two pairs must exist in order for the shield function to also exist (in addition to the pieces being on the same line).

We have the same TWO PAIRS discussed above between the queens and the bishop AND we have added a new function -- the bishop is now (3) shielding the two queens from attacking one another.  (Note: this is the basis for pins and discoveries.)

Let's look at an example with all three pieces in a line and only the first pair of functions is present, but not the second:

The limiting function of the bishop (an allied interaction) is shielding the enemy knight from the queen's attack (an enemy interaction).  This forms the basis of a discovered attack.

Let's look at an example with all three pieces in a line and only the second pair of functions is present, but not the first:

The blockading function of the bishop (an enemy interaction) is shielding the allied knight from the queen's attack (an enemy interaction).  This forms the basis of a pin.

Since the shield function requires an enemy piece to be on the board (along with other conditions...on the same line, and one of two function pairs present) the shield function should be considered an enemy interaction not an allied interaction:

Revised -- The Six Piece Interactions (or "connections")

1. Allied pieces:  (1-2) defend AND limit pair.
2. Enemy pieces:  (3) shielding, (4-5) attack AND blockade pair, and (6) restrict.

Here is a simple example showing the (6) restrict function, which was also present in the above positions but I chose not to highlight it:

The enemy pieces are interacting by attacking the same SQUARES on b8 and h8, thus restricting each other from accessing those squares.

I believe these six functions adequately cover all of the basic ways pieces interact with each other on a chess board.  These basic functions form the basis for more complex interactions, and provides the vocabulary needed to understand the more complex systems of interactions needed for the third level of vision.