Fang: Othello 101

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Othello 101

I’d like to start with a metaphor. In chess, the first step that a beginner would take is to understand the relative value of the different chess pieces. A beginner’s book on chess might start by showing the readers a short table like the following. If the total value of your pieces is more than the value of your opponents pieces then you’re probably winning.

Queen 9 pts
Rook 5 pts
Bishop 3 pts
Knight 3 pts
Pawn 1 pts


Using this simple rule, a complete beginner at chess would expect to win more than half of their games against another complete beginner who doesn’t know it. Obviously, in any undertaking as complex as chess, one simple rule falls far short of complete understanding. As a beginner becomes more advanced and progresses, they will learn new rules – as well as some exceptions to them. In much the same way, we will begin with a few basic rules of winning Othello and then build on them.

Corners Are Good

For beginning and intermediate players, games often revolve around battles for corners. As a first step, let’s take a look at a classic example of how important corners are. FangDia-20.png
White To Play


Looking at the above position, a complete beginner might assume that black is winning by a large margin. After all, black has 59 disks while white only has 1. Unfortunately, not very many of black’s disks will remain black at the end of the game, in fact, in this position, white will get to play to all four corners (because black will have no legal moves) and will win the game. It doesn’t matter what order the moves are played in as they all result in the same finishing position. Let’s look at the moves as they’re played. FangDia-21.png FangDia-22.png
WHITE PLAYS A1 WHITE PLAYS A8


White wins 40-24! FangDia-23.png FangDia-24.png
WHITE PLAYS H8 WHITE PLAYS H1


Stable disks

A reasonable question at this point might be - Why are corners important? The simple answer is that a corner is a guaranteed stable disk because there are no moves that outflank a corner. A stable disk is a disk that your opponent can never flip back to his or her color. Obviously, the more disks you have that are guaranteed to be your color at the end of the game, the more likely you are to win the game. Another great thing about corners is that you can use them to build more stable disks. Let’s take a look at another fantasy board to demonstrate how stable disks can be built from corners.


FangDia-25.png FangDia-26.png FangDia-27.png
WHITE TO PLAY WHITE PLAYS E1 WHITE PLAYS A5
Here, white can create stable disks along either the A column or the 1 row by building off of the A1 corner. An example of this follows.


Note that the 9 white disks on the edge from A1-A5 and from A1-E1 are all stable – however, the white disks on B4, C3, and D2, while they can’t be flipped in the current position, are not yet stable. For instance, if white were to play F2 then black could play G2 which would flip the D2 disk. While white is guaranteed a score of at least 9 at the end of the game, black has no stable disks at all. Let’s take a look at an example illustrating how building off of corners will result in accumulating stable disks.


Black can play either A7 or H1 and get more stable disks.

FangDia-28.png FangDia-29.png FangDia-30.png
BLACK TO PLAY BLACK PLAYS H1 – WHITE PASSES BLACK PLAYS G2
Following the rule that corners are very valuable, we will build towards the corner at H1. White will then have to pass because white will have no legal moves. Since we are building towards the H1 corner, we should try to consolidate the northeast region of the board and fill it in with black disks, in the meantime, we are going to save the move to A7 (because it won’t go away) until later. We’ll play G2 which forces white to play G3 because white has no other valid moves.


FangDia-31.png FangDia-32.png FangDia-33.png
WHITE PLAYS G3 BLACK PLAYS H3 WHITE PLAYS H2
After white plays G3, we’ll play H3 because this gives us 3 more stable disks and helps consolidate even more of the northeast region to black. Again, we’ll leave white a move here. Often, when you’re building you’ll need to leave moves for your opponent. Yes, white gets a disk at G3 and at H2 for the moment, however, look how quickly, those disks both turn into stable disks for black in that region. By forcing white to play there after black already has the corner to build off of, black can turn those disks into stable black disks.
FangDia-34.png FangDia-35.png FangDia-36.png
BLACK PLAYS H4 WHITE PLAYS H5 BLACK PLAYS H6


FangDia-37.png FangDia-38.png
BLACK PLAYS G4 BLACK PLAYS G5


Let’s stop here and assess the situation. Black already has 31 stable disks and has guaranteed that even if the 2 unstable black disks (D5 and E5) get flipped to white and white gets stable disks on the rest of the squares (very unlikely), black will still only lose the game 33-31. If black were a conservative player, black could play A7 next, which would give black 7 more stable disks and guarantee at least a 38-26 win. Unfortunately for white, black doesn’t have to play A7 which “only” wins 58-6 with perfect endgame play. Instead, black can play F7 which leads to a perfect play win by wipeout for black. A wipeout is the term for when one player ends the game with zero disks left on the board. In this game the final score after perfect play is 62-0 for black. Here’s a transcript that shows the perfect endgame from the original starting position: FangDia-39.png

TRANSCRIPT OF WIPEOUT


Later in the book, I will refer to the process of winning a clearly won game as “a matter of technique”. In the next few exercises I’m going to present you with the chance to win a few lopsided games to get a feel for how to do it for yourself.

Exercises:

For each of the following positions, set them up on a board (real or computer) and play out a forcing sequence that leads to a wipeout win. Note that in many of these positions, there are several sequences that lead to a wipeout and I’ve only provided what I consider the simplest solution.

If you find another way – good job!

1. 2.
FangDia-40.png FangDia-41.png
White To Play White To Play


3. 4.
FangDia-42.png FangDia-43.png
White To Play White To Play


Answers:

1. 2.
FangDia-44.png


FangDia-45.png


3. 4.
FangDia-46.png FangDia-47.png


A Few More Tips

While corners are good and building off of them is good, that only describes 4 squares on the board. What else can we learn about the relative values of squares?


Exercise:

Can you spot white’s two worst moves in the following position?

FangDia-48.png
WHITE TO PLAY


Answer:

B1 and B2 are white’s worst two moves.





Why? Let’s take a look at what the position would be after B1 and after B2:

FangDia-49.png FangDia-50.png
AFTER B1 OR AFTER B2


In either case, black can now take the A1 corner! None of the other valid moves for white from the starting position give black a corner on the very next turn. The thing we can learn from this is that the squares adjacent to the corner are dangerous to play into. Othello terminology has special names for these squares: C-squares and X-squares.


FangDia-51.png


C-squares are adjacent to the corner on the edge.


In the diagram to the left, the white disks are the C-squares on the board.

FangDia-52.png

X-squares are the squares that are adjacent to the corner diagonally.


In the diagram to the left, the white squares are the X-squares.


Now that we have the correct vocabulary, we can summarize what we’ve learned so far: corners are good, while C-squares and X-squares are dangerous for us to play into because if we’re not careful, our opponent will take a corner when we play into them. Even when there is no immediate threat of your opponent taking the corner, it’s usually best to stay away from C-squares and X-squares. Let’s take a look at a couple of examples:


FangDia-53.png FangDia-54.png FangDia-55.png
BEFORE WHITE PLAYS G8 AFTER WHITE PLAYS G8 BLACK PLAYS F8 AND WINS THE H8 CORNER
If white were to play G8, as diagrammed, black can’t immediately take the corner. However, at any move after this, black can choose to play F8 and after that black will be able to take the H8 corner on his or her next move.


FangDia-56.png In the left diagram, white has just played H7. After black plays H6, black is guaranteed to win the H8 corner. If white doesn’t take the disk at H6 by playing H5, black takes the corner. If white does take the disk at H6 by playing H5, black will still have a disk at H4 and black can take the H8 corner on the next turn.
WHITE PLAYS H7


FangDia-57.png FangDia-58.png FangDia-59.png
BLACK PLAYS H6 WHITE PLAYS H5 BLACK PLAYS H8


This is not to say that all C-squares are bad. In both the above examples, notice how the C-squares that were played aren’t adjacent to any other white edge disks. C-squares tend to be bad when they are isolated. They aren’t as bad when you have disks adjacent to them on the edge.


For example: In the following diagram, the C-squares at B1 and G1 aren’t a liability for black because there isn’t a way for white to attack them. In fact, as we’ll discuss later on, edges where you have 6 disks (B1 through G1 in this case) are one of the best edge formations you can have.


FangDia-60.png By not giving up corners (and avoiding playing into C-squares and X-squares which may result in losing a corner) , taking corners – when they’re available, and building off of the corners that you do get, you’ll beat almost every complete beginner that you meet.


Try playing a few games now and getting a better feel for how to apply these simple rules. You should be able to hold your own with other beginners; however, you will find many players who have advanced beyond this level. Don’t be discouraged by this, it isn’t completely unexpected. After all, I’ve only talked about one basic rule of the game, and what you do when there aren’t any corner moves available has to have some impact on the result of the game, right?



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