PAPER DECISION STUDIES
Reversi — Foundations: read the board before moving
Four starting positions, then four separate answer sheets. The IDs match the online studies.
Playfield's classic Reversi uses a six-by-six board with four starting centre discs. Violet moves first and alternates with Cream when both have legal moves. A placement must bracket one or more consecutive opposing discs between the new disc and an existing friendly disc in at least one of eight directions. Every bracketed line flips. The interface automatically passes a player with no legal move. The game ends when neither player can move, even with empty squares left; the greater disc count wins and equal counts draw. All discs count equally in this version.
Printing and using this pack
Use Print or Save as PDF. The first page contains instructions, the next four pages contain the tasks, and the remaining pages contain answers. An answer may continue onto another page. Check your print preview before choosing a page range. Print only the challenge pages if you want to keep answers separate.
Write a move and a reason before consulting the key. Rows count from the top and columns from the left. Four in a Row and Reversi diagrams state whose turn it is. The full online comparison includes all legal first moves; the answer sheets include the complete first-move comparison or a checked route.
CHALLENGE · reversi-01
Bracket before counting
Violet to move. Find a legal square, then identify every bracketed line it flips. Which available move flips the most discs in this position? This is a counting exercise, not a recommendation.
My move or route: __________________________________________
My reason: ________________________________________________
________________________________________________________
CHALLENGE · reversi-02
Count every captured line
Violet to move. Find a legal square, then identify every bracketed line it flips. Which available move flips the most discs in this position? This is a counting exercise, not a recommendation.
My move or route: __________________________________________
My reason: ________________________________________________
________________________________________________________
CHALLENGE · reversi-03
A stable corner is available
Violet to move. Which legal moves occupy a corner? Compare them with a non-corner capture and identify any corner replies you would give away.
My move or route: __________________________________________
My reason: ________________________________________________
________________________________________________________
CHALLENGE · reversi-04
Compare a corner with a larger field
Violet to move. Which legal moves occupy a corner? Compare them with a non-corner capture and identify any corner replies you would give away.
My move or route: __________________________________________
My reason: ________________________________________________
________________________________________________________
ANSWER · reversi-01
Bracket before counting
The maximum immediate capture is 1 disc, available at R2C3, R3C2, R4C5, R5C4. Only contiguous opposing discs bounded by your disc flip; an empty square breaks a ray.
Every legal first move
| First move | Immediate effect | Checked consequence |
|---|---|---|
| R2C3 | Flips 1: R3C3. | Opponent has 3 legal replies. |
| R3C2 | Flips 1: R3C3. | Opponent has 3 legal replies. |
| R4C5 | Flips 1: R4C4. | Opponent has 3 legal replies. |
| R5C4 | Flips 1: R4C4. | Opponent has 3 legal replies. |
ANSWER · reversi-02
Count every captured line
The maximum immediate capture is 3 discs, available at R3C5. Only contiguous opposing discs bounded by your disc flip; an empty square breaks a ray.
Every legal first move
| First move | Immediate effect | Checked consequence |
|---|---|---|
| R2C3 | Flips 1: R3C3. | Opponent has 6 legal replies. |
| R2C5 | Flips 1: R3C4. | Opponent has 7 legal replies. |
| R3C1 | Flips 1: R4C2. | Opponent has 5 legal replies. |
| R3C5 | Flips 3: R3C4, R3C3, R4C4. | Opponent has 5 legal replies. |
| R4C1 | Flips 1: R4C2. | Opponent has 5 legal replies. |
| R4C5 | Flips 1: R4C4. | Opponent has 9 legal replies. |
| R5C2 | Flips 1: R4C2. | Opponent has 6 legal replies, including corner R6C1. |
ANSWER · reversi-03
A stable corner is available
Legal corner moves: R1C6. A corner cannot subsequently be bracketed, so the corner disc is stable. That fact alone does not prove a full-game win.
Every legal first move
| First move | Immediate effect | Checked consequence |
|---|---|---|
| R1C4 | Flips 1: R2C4. | Opponent has 7 legal replies. |
| R1C6 | Flips 1: R2C5. | Opponent has 4 legal replies. |
| R2C3 | Flips 1: R3C3. | Opponent has 3 legal replies. |
| R3C1 | Flips 1: R4C2. | Opponent has 5 legal replies. |
| R3C5 | Flips 1: R4C4. | Opponent has 9 legal replies. |
| R4C1 | Flips 1: R4C2. | Opponent has 5 legal replies. |
| R4C5 | Flips 1: R4C4. | Opponent has 8 legal replies. |
| R5C2 | Flips 1: R4C2. | Opponent has 6 legal replies, including corner R6C1. |
| R5C4 | Flips 1: R4C4. | Opponent has 7 legal replies. |
| R6C5 | Flips 1: R6C4. | Opponent has 5 legal replies. |
ANSWER · reversi-04
Compare a corner with a larger field
Legal corner moves: R1C6. A corner cannot subsequently be bracketed, so the corner disc is stable. That fact alone does not prove a full-game win.
Every legal first move
| First move | Immediate effect | Checked consequence |
|---|---|---|
| R1C6 | Flips 1: R2C5. | Opponent has 5 legal replies. |
| R2C1 | Flips 1: R3C2. | Opponent has 6 legal replies. |
| R2C3 | Flips 1: R3C3. | Opponent has 5 legal replies. |
| R3C1 | Flips 3: R3C2, R3C3, R4C2. | Opponent has 4 legal replies. |
| R3C5 | Flips 1: R4C4. | Opponent has 8 legal replies. |
| R3C6 | Flips 1: R2C5. | Opponent has 6 legal replies. |
| R4C1 | Flips 1: R4C2. | Opponent has 8 legal replies. |
| R4C5 | Flips 1: R4C4. | Opponent has 8 legal replies. |
| R5C1 | Flips 2: R4C2, R3C3. | Opponent has 7 legal replies. |
| R5C4 | Flips 1: R4C4. | Opponent has 8 legal replies. |
| R6C5 | Flips 1: R6C4. | Opponent has 6 legal replies. |