Fang: More Othello Concepts

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Gier ist eine der sieben Todsünden

Im letzten Abschnitt habe ich über die Bedeutung von Ecken gesprochen. Offensichtlich sind Ecken zu Beginn des Spiels nicht greifbar. Was du als nächstes wirklich wissen willst ist: Welche anderen Regeln kann ich während des restlichen Spiels befolgen, damit ich eine Chance habe, mehr als nur Anfänger zu schlagen? Wenn du meinen Rat befolgst und ein paar Partien mit einigen Anfängern und fortgeschrittenen Spielern gespielt hast, hast du vielleicht schon ein Muster bemerkt.


Lass uns einen Blick auf eine Beispielposition werfen::

FangDia-61.png Welche Vorteile hat Weiß in der linken Stellung? Er hat sicherlich viele Steine. Für das ungeübte Auge sieht es vielleicht sogar so aus, als ob Weiß weit vorne liegt (schließlich hat Weiß mehr Steine!). Aber wenn du genauer hinsiehst, hat Weiß in der obigen Stellung nur 2 gültige Züge, während Schwarz am Zug ist. Und was noch schlimmer ist, diese beiden Züge lassen Schwarz kurz darauf die Ecke bekommen. Aus dem letzten Abschnitt wissen wir, dass das schlechte Nachrichten für Weiß sind. Zum Glück für Weiß – muss Schwarz hier den Zug spielen. Schwarz hat viele Möglichkeiten, vom absolut schrecklichen G2 (eine Ecke aufgeben) über B5 bis E1. Wenn Schwarz hier B5 spielen würde, würde Weiß dann A5 oder B6 spielen (da die anderen 3 gültigen Züge in der Stellung eine Ecke verschenken würden).
SCHWARZ IST AM ZUG


FangDia-62.png FangDia-63.png Das hat Schwarz nicht vorangebracht und Schwarz ist wieder dran. Was wäre, wenn Schwarz hier stattdessen A5 spielen würde? Weiß würde A6 antworten (weil Schwarz dann droht, die Ecke zu nehmen, indem es entlang der A-Kante spielt, wenn Weiß B5 spielen würde).
SCHWARZ SPIELT B5 WEISS SPIELT A5


FangDia-64.png FangDia-65.png Auch das bringt nicht viel. Unglücklicherweise für Weiß hat Schwarz hier einen viel besseren Zug, E1. Nach E1 hat Weiß nur noch die gleichen 2 Züge, die die Ecke verlieren.
SCHWARZ SPIELT A5 WEISS SPIELT A6


FangDia-66.png Ich nenne Züge wie E1 gerne den Killerzug, denn danach ist das Spiel praktisch vorbei und es geht nur noch darum, die Ecke bestmöglich zu erreichen und von dort aus stabile Steine aufzubauen. In ähnlicher Weise gibt es oft Sequenzen von 2 oder mehr Zügen, die sofort gewinnen, und ich nenne diese Killersequenzen.


In der Othello-Terminologie ist ein leiser Zug ein Zug, der die Position nicht sehr stört, also wenig verändert. Andererseits ist eine lauter Zug ein Zug , die die Position erheblich verändert. Tatsächlich ist E1 im obigen Beispiel ein perfekter leiser Zug, weil er genau 1 Stein umdreht und dem Gegner keine neue Zugmöglichkeit bietet (daher ist es so leise, wie es ein gültiger Zug in Othello maximal sein kann – er verändert das Brett fast nicht). Um es noch ein bisschen zu verdeutlichen - dein Gegner wird die gleichen (oder weniger) Zugmöglichkeiten haben als zuvor, nachdem du einen perfekten leisen Zug spielst. Im linken Beispiel kann Weiß zu B1 und B2 spielen, bevor Schwarz E1 spielt. Nachdem Schwarz E1 spielt, kann Weiß immer nur noch auf B1 und B2 spielen, genauso wie vor dem Zug Schwarz E1. Als allgemeine Regel gilt: Wenn es einen vollkommen leisen Zug auf dem Brett gibt, ist es fast immer richtig, ihn zu spielen.

SCHWARZ SPIELT E1


Was können wir aus der obigen Position lernen? Mit gutem Spiel kannst du deinen Gegner dazu zwingen, dir Ecken zu geben – selbst wenn er weiß, wie wertvoll Ecken sind und vermeidet, auf X-und C-Felder zu spielen. Die eigentliche Frage ist: Wie kommst du in Positionen, in denen dein Gegner dir eine Ecke geben muss?


Schauen wir uns ein anderes Beispiel an:

FangDia-67.png FangDia-68.png FangDia-69.png
SCHWARZ IST AM ZUG SCHWARZ SPIELT H6 WENN WEISS G1 SPIELEN WÜRDE
Schwarz kann den vollkommen leisen Zug nach H6 spielen, woraufhin Weiß auf 4 Arten reagieren kann: H2, H3, G2, G1. Wir können ziemlich sicher sein, dass Weiß nicht G1 spielen wird, da dies Schwarz sofort eine Ecke gibt.


H3 mag gut erscheinen, aber nach H3 kann Schwarz H2 spielen und Weiß wird gezwungen sein, G2 oder G1 zu spielen – beide verlieren die Ecke. FangDia-70.png FangDia-71.png
WENN WEISS H3 SPIELT SCHWARZ SPIELT H2


G2 ist nicht viel besser als H3. Tatsächlich kann Weiß nur versuchen, sich zu behaupten, indem es H2 spielt, ein gefährliches (aber notwendiges) C-Feld. Nachdem Schwarz als Antwort C1 gespielt hat, muss Weiß E1 oder D1 spielen. FangDia-72.png FangDia-72.png FangDia-73.png
WENN WEISS H2 SPIELT SCHWARZ SPIELT C1


White only has these 2 moves that don’t give up the corner – both are on the north edge. No matter which of these moves to the north edge that white plays next, black will play the other. If white plays D1, black will play E1, and vice versa, we call such moves paired – when the obvious response to a move is another move and vice versa. After the move pair is played out, white will be forced to give up the H1 corner on his next turn. FangDia-74.png FangDia-75.png
IF WHITE PLAYS D1 BLACK PLAYS E1


FangDia-76.png FangDia-77.png
IF WHITE PLAYS E1 BLACK PLAYS D1


So if it’s black’s turn, white will lose. What about if it’s white’s turn? White could play H3 ,making a black move to H6 pointless (White just plays H7 after H6), however then black will just play E1 instead, forcing white to play D1 and then black will play C1 forcing white to lose a corner.


Obviously, whatever it is about the previous starting positions that is bad, it carries over no matter whose turn it is. In order to figure out how to force our opponents to give us corners, we need to figure out what features the two diagrammed positions have in common. White’s real problem in both positions is that he doesn’t really have a lot of options to begin with and the options that he has aren’t very good. When you have lots of moves to choose from you are said to “have lots of mobility”. When you don’t have many moves to choose from you are “low on mobility”. Having good mobility(having good moves) is a very important part of the game. If you have a lot of mobility – at least a few of those moves are bound to be good. And the opposite is true, if you don’t have very many moves – you might not have any good moves at all.


Many games between an expert and a beginner are decided in terms of mobility alone. The expert quickly runs the beginner out of good moves, and then forces the beginner to give up a corner (by leaving the beginner one or two moves that both lose a corner) and from there it’s all a matter of technique.


Why doesn’t white have much mobility in the above diagrams? Because black doesn’t have a lot of disks., Obviously if black only has 3 or 4 disks, white will probably have only 2 or 3 moves. If those 2 or 3 moves are all moves that give away a corner, then black is probably going to win. The point I’m trying to make here is that by having fewer disks, you can get into positions where your opponent is forced to give you a corner. Having fewer disks is actually better most of the time!


Unfortunately, this can be a very difficult lesson to learn. The “goal” of the game is to get the most disks, right? Wrong. The goal of the game is to have the most disks at the end of the game. We’ve already seen how having corners leads to stable disks and we know that stable disks lead to more disks at the end of the game. In between the start and the end of the game, our goal is to put ourselves into a position where we’re likely to have the most disks at the end of the game. If this means having fewer disks in the opening and midgame, then so be it.


Exercises:

Now that we’ve seen a little bit about how we can force our opponents to give us a corner – these exercises will help us find the killer moves that are necessary to get the job done. Find a move or short sequence that forces your opponent to give you a corner. Note that in most of these positions there are multiple answers. I’ve picked the shortest killer sequence as the answers. If you found another forced sequence, good job! 1.                                        

FangDia-78.png

2.                                        

FangDia-79.png

SCHWARZ IST AM ZUG SCHWARZ IST AM ZUG


3.                                        

FangDia-80.png

4.                                        

FangDia-81.png

SCHWARZ IST AM ZUG SCHWARZ IST AM ZUG


Answers:

1.                                        

FangDia-82.png

2.                                        

FangDia-83.png

3.                                        

FangDia-84.png

4.                                        

FangDia-85.png


Exercises:

Find the Perfectly Quiet Move in each of the following positions: 1.                                        

FangDia-86.png

2.                                        

FangDia-87.png

SCHWARZ IST AM ZUG SCHWARZ IST AM ZUG
3.                                        

FangDia-88.png

4.                                        

FangDia-89.png

BLACK OR WHITE TO PLAY WHITE TO PLAY


Answers:

1. F4 2. H5 3. C6 is a Perfectly Quiet Move for BOTH players 4. H4


Don’t leave yourself high and dry

Let’s say that your opponent is trying to maximize their disks. At some point in the game, you’re likely to get wiped out if you completely commit yourself to minimizing your disks. The term for this situation is overevaporation. Unfortunately, you can’t always focus on just minimizing your disks,you sometimes have to pay attention to make sure that you’re not going to wipe out. Remember having fewer disks is a means to forcing your opponent to give you corners, it is not an end in and of itself.


In order to avoid being wiped out by someone who is playing greedily, you’ll want to try to play moves that do 1 of 3 things (in this order of importance):

  • Establish a stronghold on an edge that your opponent can’t flip
  • Play a move that flips disks in more than one direction at once
  • Play a move that makes a line that is not immediately reflippable.


Let’s take a look at examples of each of these in turn.


Establish a stronghold on an edge that your opponent can’t flip

Edge disks are harder to flip than regular disks as they can only be flipped by other disks on the edge, instead of in 8 different ways like all the other disks. By establishing a stronghold on the edge and not letting your opponent flip those disks, you guarantee yourself that you’ll have some disks to play off of later in the game.


FangDia-90.png FangDia-91.png In the left example, black could play moves like E7 or E2 that immediately get wiped out. For instance, if black played E7 white would play E8. In order to avoid being wiped out, black can try to establish a stronghold on an edge that White will never be able to flip. For instance, if black were to play H5, then white can never take black off of the edge because no matter where white plays along the edge, black can just capture along the edge and protect his stronghold.
SCHWARZ IST AM ZUG BLACK PLAYS H5


FangDia-92.png FangDia-93.png For instance, if white tries to get on the edge with H4, black will just take the edge with H3. As long as white can’t take black’s edge disks, black can’t be wiped out. Notice that in the original diagram black had several other possible edge moves (A5, H4, H7), however, H5 is the quietest move and it leaves white with the fewest options (in fact , it’s an easy win for black), and that makes H5 the correct choice.
WHITE PLAYS H4 BLACK PLAYS H3


Flip in more than one direction at once

If you are dangerously low on disks, flipping more disks will help you avoid being wiped out. That is one of the reasons that flipping in more than one direction at once is good. You tend to flip more disks when you flip in more than one direction. Also, your opponent can never wipe you out on the move immediately following a move in which you’ve flipped in more than one direction.


FangDia-94.png FangDia-95.png In this position, establishing a stronghold on the edge by playing C8 doesn’t work because then white plays E8 and neither player has any more legal moves (and thus white wins). Obviously another idea is in order. An example safe move is for black to play B4 which flips disks in 2 directions. After this move, white can’t wipe black out during his or her next move.
Black To Move Black Plays B4


Make a line that is not immediately reflippable

Obviously if a line is not immediately reflippable then your opponent can’t wipe you out on the next move. Making a non-reflippable line is usually a delaying tactic that you will use until you can play moves that meet one of the two above criteria.


FangDia-96.png FangDia-97.png In the example, if it were white’s move, white would play H2 or G2 and wipe black out. Since black has no moves that establish a stronghold on an edge – nor does he have any moves that flip in more than one direction at once, black’s only reasonable moves are ones that makes a line that white can’t immediately reflip. In this case there are 2 moves that meet our criteria - C7 and G7. Obviously black doesn’t want to give white the corner so black should play C7 here. The move to C7 forms a line between C7 and G3 that white cannot immediately reflip the next turn. Now, regardless of what white lays, black will have moves like H6 and B4 next move which will avoid being wiped out.
SCHWARZ IST AM ZUG BLACK PLAYS C7


What’s in an edge

Let’s take a look at another position and see what we can learn from it:


FangDia-98.png So you’re looking at the position and you’re wondering “OK, black has a lot fewer disks and white has very poor mobility. How does black win a corner?” The answer is: black can’t win a corner in this position (at least – not in the next couple of moves). What’s different about this position? Because of black’s disk placement, white only has one “dangerous” move that he could play if it were his turn, A2. It is very easy for white to avoid playing to A2.
SCHWARZ IST AM ZUG


Let’s play fantasy Othello for a bit and move one disk on the board slightly


FangDia-99.png Now black does have a move that wins a corner (black plays B1 and white must play B2). You should notice that in the second diagram, the disk that previously was in the middle of the board is now on the edge. In fact, in all of the winning positions that were presented in the last chapter as examples (and in the current example as well), all of the correct moves for black to play (because they force white to lose a corner) were edge moves. As mentioned in the last chapter, edge disks can only be flipped along the edge so this means that edge moves tend to be quieter than non-edge moves. Quieter moves give your opponent fewer options the next turn. Eventually if you can play enough quiet edge moves, your opponent will run out of other moves and have to give you a corner. This simple strategy is known as edge creeping because you are attempting to creep slowly along the edge until you win a corner.
SCHWARZ IST AM ZUG


Another thing that you should notice is that in the original diagram, the black disk is on the outside of the mass of white disks where it could be flipped – which means that white has a couple of possible moves to begin with. Disks that are on the outside of a mass of opposite colored disks that can be flipped are called frontier disks. The edge disk in the second example isn’t a frontier disk at the current time because it can’t be flipped. In the future, white may get a disk at D1 or black could play to D1 in which case C1 would become a frontier disk. Since every frontier disk provides your opponent with a potential move, having,fewer frontier disks mean that you have a better position.


Now that I’ve set some general guidelines, we’ll spend the next few chapters exploring the three phases of the game: the opening, the midgame, and the endgame. We’ll look at how to apply these guidelines to the three phases of the game as well as when these guidelines no longer apply.



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