Tactic Calculation

Question 1

What are the seven calculation steps?

Answer 1

Step 1 MI (material & imbalances)
Step 2 OT (opponent’s threats)
Step 3 UP (any hanging / unprotected / semi-protected pieces)
Step 4 TT (tactical themes)
Step 5 CH (any checks)
Step 6 CM (any checkmate threat?)
Step 7 FM (forcing moves)

Question 2

What is step 2 (OT)?

Answer 2

Step 2 OT (opponent’s threats)
What are opponents threats? checks, mate, unprotected, semi, tactical themes

Question 3

What is step 1 (MI)?

Answer 3

Step 1 MI (material & imbalances) Count the material and identify any material imbalance.
How does that effect decision making e.g. if pawn / piece down then different choices

Question 4

What is step 5 (CH)?

Answer 4

Step 5 CH (any checks) Can I give a check? (Checks are the most forcing moves you can do)

Question 5

What is step 6 (CM)?

Answer 5

Step 6 CM (any checkmate threat?) Can I threaten checkmate? (The checkmate threat is the second most forcing move one can do)

Question 6

What is step 3 (UP)?

Answer 6

Step 3 (unprotected pieces and pawns

Look for Hanging Pieces / Unprotected pieces / Semi protected pieces

HP (hanging pieces) - A piece immediately under threat of capture.

UP ( unprotected pieces) - A piece / pawn with no protection, 0 pieces defending and 0 attacking

SP (any semi-protected pieces) - a piece / pawn that has the same number of attackers and defenders e.g.

• 1 attacker - 1 defender
• 2 attacker - 2 defender
• n attacker - n defender

These often deserve more attention that unprotected pieces.

Remember LPDO - Loose Pieces Drop Off

An unprotected piece is a target for an attack threat.

Question 7

What is step 6 (TT)? What are the two mnemonics?

Answer 7

Step 6 - TT (tactical themes) What are the tactical themes?

HUSXM

TPDCLS

1. Hanging pieces
   - existing threat
   - # attack > # defend
2. Unprotected pieces and semi-protected pieces
   - potential threats
   - # attack = # defend
   - Add an attacker
   - Remove a defender – decoy / distraction
   - Interfere with a defender – cut off protection
3. X ray attacks - An X-ray attack refers to a situation where a long-range piece indirectly attacks an enemy piece through another piece or pieces - indirect - does this alter hanging / unprotected?
4. Mating possibilities.
   - Among its variations, the simplest pattern is a weak back rank. This refers to a situation where the defender has either one or no major piece guarding his back rank and has not moved any pawns in front of his King.
5. Trappable pieces - Is there a piece that can barely move - if attacked cannot run away
6. Pinned, pinnable, forkable, and skewerable pieces
7. Discovered attack / discovered check
8. Critical lines and squares
   Weak squares / colour complexes
   Is there an alignment of pieces offering opportunity along a diagonal, rank or file especially where heavy pieces are involved?
   - Diagonal - bishop , queen
   - File (vertical) - rook, queen
   - Rank (horizontal) - rook, queen

Question 8

What is step 7 (FM)?

Answer 8

Step 7 FM (forcing moves)

Consider forcing moves and calculate them to the best of your ability!

Forcing moves that force the opponent to respond in a limited way

• create a threat
• win material
• win game
• improve position

Question 9

In what sequence should forcing moves be considered?

Answer 9

You should always start with the most forcing ones (checks > checkmate threats > capturing or threatening the highest valued piece and so on) all the way down to the least forcing ones (attacking a pawn).

most forcing move
- checks
- checkmate threat
- highest captures
- queen, rook
- attack a piece
- e.g. pawn moves
- huge material gain threat
least forcing move
- attack a pawn
attacks threaten to win next move
but gives opponent 2 moves to react

Question 10

Tactical themes 1 - what is a hanging piece?

Answer 10

1. Hanging pieces
   - existing threat
   - # attack > # defend

Question 11

Tactical themes 2 - what are unprotected and semi-protected pieces?

Answer 11

2. Unprotected pieces and semi-protected pieces
   - potential threats
   - # attack = # defend
   - Add an attacker
   - Remove a defender – decoy / distraction
   - Interfere with a defender – cut off protection

Question 12

Tactical themes 3 - what are X ray attacks

Answer 12

3. X ray attacks - An X-ray attack refers to a situation where a long-range piece indirectly attacks an enemy piece through another piece or pieces - indirect - does this alter hanging / unprotected?

Question 13

Tactical themes 4 - what are Mating possibilities.

Answer 13

4. Mating possibilities.
   - Among its variations, the simplest pattern is a weak back rank. This refers to a situation where the defender has either one or no major piece guarding his back rank and has not moved any pawns in front of his King.

Question 14

Tactical themes 5 - what are Trappable pieces.

Answer 14

5. Trappable pieces - Is there a piece that can barely move - if attacked cannot run away

Question 15

Tactical themes 6 - what are Pinned, pinnable, forkable, and skewerable pieces

Answer 15

6. Pinned, pinnable, forkable, and skewerable pieces

Question 16

Tactical themes 7 - what are Discovered attack / discovered check

Answer 16

7. Discovered attack / discovered check

Question 17

Tactical themes 8 - what are Critical lines and squares

Answer 17

8. Critical lines and squares

• Diagonal - bishop , queen
• File (vertical) - rook, queen
• Rank (horizontal) - rook, queen

Is there an alignment of pieces offering opportunity along a diagonal, rank or file especially where heavy pieces are involved?

Question 18

What are the eight tactical themes to consider?

Answer 18

1. (HP) Hanging pieces
2. (UP/SP) Unprotected pieces and semi-protected pieces
3. (XRAY) X ray attacks
4. (CM) Mating possibilities.
5. (TP) Trappable pieces
6. (PFS) – Pins, forks and skewers - Pinned, pinnable, forkable, and skewerable pieces
7. (DA/DC) Discovered attack / discovered check
8. (CLS) Critical lines and squares

Question 19

What are the 3 ways to threaten and win an unprotected or semi-protected piece?

Answer 19

There are three ways to threaten / win a unprotected and semi-protected pieces

1. add an attacker
2. remove a defender
   * decoy / distraction tactical motif
3. interfere with a defender’s protection

• cut off the protection
• quite rare
• e.g. put a pawn / piece in between piece anf defender of piece

Question 20

What is HUSXM?

Answer 20

HUSXM is the first part of tactical themes

1. (H) Hanging pieces
2. (US) Unprotected pieces and semi-protected pieces
3. (X) X ray attacks
4. (M) Mating possibilities.
5. Hanging pieces
   - existing threat
   - # attack > # defend
6. Unprotected pieces and semi-protected pieces
   - potential threats
   - # attack = # defend
   - Add an attacker
   - Remove a defender – decoy / distraction
   - Interfere with a defender – cut off protection
7. X ray attacks - An X-ray attack refers to a situation where a long-range piece indirectly attacks an enemy piece through another piece or pieces - indirect - does this alter hanging / unprotected?
8. Mating possibilities.
   - Among its variations, the simplest pattern is a weak back rank. This refers to a situation where the defender has either one or no major piece guarding his back rank and has not moved any pawns in front of his King.

Question 21

What is TPDCLS?

Answer 21

TPDCLS is the second part of tactical themes

5. (T) Trappable pieces
6. (P)Pinned, pinnable, forkable, and skewerable pieces
7. (D) Discovered attack / discovered check
8. (CLS) Critical lines and squares
9. Trappable pieces - Is there a piece that can barely move - if attacked cannot run away
10. Pinned, pinnable, forkable, and skewerable pieces
11. Discovered attack / discovered check
12. Critical lines and squares
    Weak squares / colour complexes
    Is there an alignment of pieces offering opportunity along a diagonal, rank or file especially where heavy pieces are involved?
    - Diagonal - bishop , queen
    - File (vertical) - rook, queen
    - Rank (horizontal) - rook, queen