Fang: Simple Endgame Advice

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  • Build on what you already know
  • More is More
  • Rules are made to be broken …


Now it’s time to finish off your opponent with a flourish. The corners that your opponent had to give you are now turning into anchors from which you’ll build your empire. The first order of business is to consolidate to your color as many disks near your corner as possible. As disks near your corner are captured, more and more of them will become stable. If your position is good enough, you’ll even have a chance to build in a way that will force your opponent to give you another corner. After taking that second corner, you can consolidate around it as well. Let’s look at a quick example: FangDia-130.png FangDia-131.png
STARTING POSITION BLACK PLAYS G3


There are several ways to consolidate disks near the H8 corner – because the disk at G6 is closer to H8 than any of the other white disks, we’ll play G3 – which flips that disk in the least disruptive way possible. Notice that D3 would also flip the G6 disk – however, after G3, white has 2 options, after D3, white has 6 options. Once your have your opponent under control, its better if you keep them under control and limit what they can do. The more options they have, the more complicated the position will become and the more complicated the position is, the easier it is to make a mistake that will lose disks. While black isn’t in any danger of losing after D3, white may be able to salvage 15-20 disks if black plays inaccurately. However, after G3 white is still in danger of being wiped out, even if black makes a few minor errors. It’s also much easier to calculate ahead when your opponent only has one or two options because then you can concentrate on finding your best moves instead of having to worry about them fighting back.


After G3, white has 2 options, H3 and H2. Let’s look at both: FangDia-132.png FangDia-133.png
WHITE PLAYS H3 BLACK PLAYS H2


OR FangDia-134.png FangDia-135.png
WHITE PLAYS H2 BLACK PLAYS C7


If white plays H3, then black plays H2. White has to play G2 the next move and black will easily take the northeast corner. If white plays H2, then black plays C7 and then white is forced to play H3 also giving up the corner. After taking the northeast corner, black will consolidate around that corner as well and will have an overwhelming advantage.


Exercises:


In the following diagrams, find a wipeout sequence. In most of the puzzles there is more than one wipeout sequence but only one solution is given, if you find another - good job! I’ve deliberately made these exercises quite a bit harder than the previous ones on building. In fact, I had a lot of trouble with the #3 and #4 myself! These more difficult puzzles are meant to hone your skills to the point that they’re razor sharp. With a little more practice, winning this type of position will become second nature to you. 1.                                         2.                                        
FangDia-136.png FangDia-137.png
BLACK TO PLAY BLACK TO PLAY



3.                                         4.                                        
FangDia-138.png FangDia-139.png
BLACK TO PLAY BLACK TO PLAY


Answers:


1.                                         2.                                        
FangDia-140.png FangDia-141.png



3.                                         4.                                        
FangDia-142.png FangDia-143.png


Counting and Basic Endgame Theory

Of course, building is only going to help when you’re way ahead. At some point in a closer game you have to remember that you want to have the most disks at the end and more importantly the end is getting near. You are trying to keep the number of disks that you have to a small number as suggested in the previous sections, right?


Obviously, at the end of the game, keeping your disks to a minimum is not as good of an idea. You have to start playing moves that take a lot of disks. Usually, in a fairly even game, this is when there are about 8 or 10 empty squares on the board. Unfortunately there’s no hard or fast rule for when you should start taking a lot of disks, however, if you can take a lot of disks and most are stable or they make other disks that you have stable, then it is probably a good idea.


FangDia-144.png We’ll start with the simple example shown left. We’re at the last 2 moves of the game – so this should be easy. This process of calculating the best play sequence is called counting. Counting is a difficult skill to master and there are many strategies for it. I prefer to simply employ a plus minus count of disks and see which sequence is “optimal”.


Let’s count black’s move to A1 first. Black plays A1, that’s +5 black disks. White Plays A2 (flipping B2), that’s -1 black disk. So +5 – 1 = +4 black disks. The sequence where black plays A1 ends up with 4 more disks than in the original position. That’s not bad.


Just to be on the safe side, let’s check and make sure that the move to A2 doesn’t get more disks. Black plays A2 and gets +9 black disks. White plays A1 and flips B2 and A2, that’s -2 black disks. +9 – 2 = +7 black disks!

BLACK TO PLAY


So, taking the corner in this case is the wrong move. In fact, if we count the disks currently on the board, black has 26 disks. 26 + 4 = 30. Black loses 30-34 if he takes the corner. 26 + 7 = 33. Black wins 33-31 if he plays A2. The difference between winning and losing is in understanding why this is the case. For one thing, the move to A2 simply flips more disks. With only 1 move left, white can’t flip enough of them back to make the corner worth very much. Remember, the reason that corners are important is that they tend to lead to stable disks. Here, there isn’t anywhere for white to build off of, so the corner isn’t worth very much. What we can learn from this fiasco is that rules are meant to be broken and that corners become worth less late in the game because there are fewer opportunities left to build from them.



FangDia-145.png In this example, Black has 3 choices. Obviously A2 (giving up the corner for no reason) isn’t helpful, so let’s look at the other 2 options and how they play out.


B1 - After B1, white is forced to play to B2. The position after B1 B2 should look familiar because it is the position from the previous example! After B1 B2, Black would play A2, winning 33-31.


B2 – This flips 14 disks and many of them become stable.

  • If White Plays B1 (-3) – Black Plays A1 (+2) then White Plays A2.(-2) – +14 -3 +2 -2 = +11
    • If White Plays A2 (-1) then Black Passes
      • If White Plays A1 (-5) then Black plays B1 (+3) +14 -1 -5 +3 = +11
      • If White Plays A2 (-4) then Black Plays A1 (+3) +14 -1 -4 +3 = +13
    • If White Plays A1 (-5)
      • If Black Plays B1 (+2) then White Plays A2 (-1) +14 -5 +2 -1 = +10
      • If Black Plays A2 (+2) then White Plays B1 (-3) +14 -5 +2 -3 = +8
BLACK TO PLAY


After all this calculation, we see that the best sequence after B2 is A1 B1 A2. +10. In the original position, Black has 25 disks. This means that with perfect play black will win 35-29. Since 35-29 is better than 33-31, B2 is the best move for black in the example position. Clearly being greedy and playing B2 and flipping a lot of disks works out well in this position.


FangDia-146.png Before we get too greedy and always start playing the move that flips the most disks on the board let’s take a look at the left position.


  • If Black Plays A1 (+2) – White plays A2 (-1) = +1
  • If Black Plays A2 (+9) – White plays A1 (-10) = -1


Oops! Even though the move to A2 flips more disks, it’s the wrong move. By playing to A2, black lets white flip all the disks on the A1-H8 diagonal as well as all the new black disks on the A edge.


One of the most difficult parts of Othello is playing proper endgames because at times the right sequence is nearly impossible to see without counting every possible variation, and that quickly becomes impossible, even for master level players. Even top human players make endgame errors, however, the errors that they make tend to be small (2 or 4 disks) and they tend get a lot of the moves right. On the other hand, I’ve watched games between beginners where both players trade endgame errors that are 8 to 10 disks wrong at almost every move.


One important rule we can follow when counting is to know that in almost all cases, if we have a sequence in which we get all of the remaining moves, it will probably be the best sequence.


FangDia-148.png If I were to sit down at this game I would immediately play A1 as white. After playing A1, black is forced to pass. Then white plays B2 as well. If white were to play B2 first, black would be able to play A1. If I can get all the disks I would get by playing B2 AND all the disks from playing A1, it has to be better than just getting the disks from playing B2 (-2 because black flips the A2 and B2 disks when he plays A1). If we were to sit down and count this position. We would find out that A1 wins 39-25 while B2 loses 30-34.
WHITE TO PLAY


FangDia-149.png If I were to sit down at the left game I would immediately play A1, Pass, B1, Pass, H8 and I get all 3 moves. Clearly, playing B1 isn’t good as white just plays A1 and black doesn’t get the A1-H8 diagonal. If black were to play H8 first and then A1 white would just play B1 because the B2 disk would get flipped. Without even bothering to count I know that A1 then B1 then H8 has to be best.
BLACK TO PLAY


Exercises:


Because people DO make errors, even with 3 or 4 empty – it is in your best interest to learn how to play simple endgames correctly. Not only will you win close games that are “won” for you, you’ll also win some close games where your opponent will make a mistake or miscount. In the following exercises, find the winning sequence. 1.                                         2.                                        
FangDia-150.png FangDia-151.png
BLACK TO PLAY WHITE TO PLAY



3.                                         4.                                        
FangDia-152.png FangDia-153.png
WHITE TO PLAY WHITE TO PLAY


Answers:


1.                                         2.                                        
FangDia-154.png FangDia-155.png
BLACK WINS 33-31 WHITE WINS 33-31


3.                                         4.                                        
FangDia-156.png FangDia-157.png
WHITE WINS 33-31 WHITE WINS 40-24



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