Tuesday, July 20, 2010

ZERTZ - How to force a win?

Article by: Karina


How to force a win in Zértz


I really love Zértz. I discovered this beautiful game half a year ago, and it was love at first sight. The rules are easy, but the game is hard to master. And the playing time is short.

I've studied Zértz a bit (37 rings where you need 4 whites, 5 greys, 6 blacks or 3 of each to win). And I found that if you play second and your opponent removes a ring to the edge (not a corner ring), you can force a win wherever he/she places the first marble and no matter what color it is. If your opponent starts by removing a corner ring, there are only 13 "safe" places the marble can be placed. If the marble is placed on any of the other 23 places, you can force a win. This was really surprising to me. Of course this theory won't work if Zértz is played with more rings.

I've divided the method into two parts. In the first part you can give away up to six marbles, get two whites by isolation and leave the board empty. In the second part you can give away up to five marbles, isolate another two white marbles and win.

Before I show you the theory, I'll list a few things you have to remember:

Never give the initiative to your opponent, - always force a jump unless you leave the board empty.

Keep a close eye on your opponets marbles when you place marbles, - don't pick a marble that will give away the victory.

Be careful to place the white marble you want to isolate, at the right time.

Don't leave a ring where your opponent can isolate the first marble in part two.

You can force your opponent to jump in the direction you want, by removing rings.

Part 1

In the first part you can afford to give six marbles, for example three blacks, two greys and one white. A total of eight rings can be removed: the one your opponent removes and the seven rings you are allowed to remove in order to isolate two white marbles. The result has to look something like this:



A non-corner ring is removed




So, let's see how it works. And we'll start with the situation where your opponent removes a non-corner ring at the edge and places a marble anywhere on the board. The board will then look like this with one single marble places somewhere: (You may have to rotate or flip it to get a match.)

And when you see this, you'll know that you can force a win. How? I'll show you. First take a look at this diagram:


Let's suppose that the removed ring is at a2 (remember you can twist the board to match your situation). If the marble is placed in the red area, you can isolate two white marbles on a1 and b1. If the marble is placed in the blue area, you can isolate two white marbles on a4 and b5. If the marble is placed in the green area, you remove a3 and places a marble on the green ring just above or below the first marble. If your opponent jumbs into the red area, you go for the red strategy with a1 and b1. And if he/she jumps into the blue area, you go for the blue strategy with a4 and b5.




There are in fact more possibilities if for example the marble is placed on the edge somewhere, but for simplicity we don't include that now. Just focus on the red strategy with a1 and b1 and the blue strategy with a4 and b5.



So, now that you've got a goal, you need to know how to get there. You have to both prepare an isolation area and force a jump onto it at the right time.



In the red strategy you have to remove a3, b3, b2, c3, c2 and last c1. In most cases you also have to remove g1 to force a jump with a white marble onto d1. Click here to see how to do it in the specific cases.

In the blue strategy you have to remove a3, b3, b4, c4, c5 and last c6. In most cases you also have to remove g4 to force a jump with a white marble onto d7. Click here to see how to do it in the specific cases.

In the green strategy you first remove a3 and places a marble just below or above the first marble, and your opponents first jump decides how you continue. Click here to see how to do it in the specific cases.

A corner ring at the edge is removed

If your opponent removes a corner ring, you are not sure to win. Let's suppose the removed ring is g1 (remember you can twist the board to match your situation) and take a look at this diagram:



If the marble is placed in the red area, you can isolate two white marbles on a1 and b1. If the marble is placed in the blue area, you can isolate two white marbles on d7 and e6. If the marble is placed in the green area, you can isolate two white marbles on the ring the first marble is placed and a neighboring green ring. There are more possiblities, but for simplicity we don't include that now.




If the marble is placed on one of the 13 black rings, I don't know how to force a win. It might work, but that depends on where your opponent places the first marble in part two. You can't take that risk. Instead I'll advise you to just place a marble somewhere smart, and continue thinking throughout the game. Good luck!



Let's suppose the marble is not placed in the safe black area. Now you can both prepare an isolation area and force a jump onto it at the right time.



In the red strategy you have to remove a3, a2, b3, b2, c3, c2 and last c1. You may have to use the removed g1 to force a jump with a white marble onto d1. Click here to see how to do it in the specific cases.

In the blue strategy you have to remove c6, b5, c5, d6, d5, e5 and last f5. You may have to use the removed g1 to force a jump with a white marble onto g4. The blue strategy is simply a reflection of the red strategy.

In the green strategy you have to remove five rings in order to isolate two whites on the ring the first marble is placed and a neighboring green ring. Click here to see how to do it in the specific cases.

Part 2

In part two you have to be creative. You leave the board like this if you use the red (left) or blue (right) strategy:


Note that the two pictures are flipped and rotated, and can therefore be handled identically.

If a corner ring is removed and a marble placed in the green area, the board looks like this:
The problem is that your opponent can place a marble anywhere and removes any ring at the edge. This results in many different situations. (27 alternative places to place the ring, and 16 alternative rings to remove gives a total of 27*16=432 different possiblities.) So let's look at the possibilities in general. You can offer up to five marbles and remove six rings in order to isolate two white marbles without loosing the initiative. You can either isolate the two white marbles on the same side or one on each side. This works well, in fact I still haven't found a case that breaks the theory.


Let's suppose you've used the red strategy. Here's a few examples on what to do:

Your opponent places any marble on f2 or g2 and removes any ring but a4, d3, e1 and f1:

Note that in this case you isolate one white marble on each side of the board.

Your opponent You

15. Nf2/g2,nn 16. Ng2/f2,b5
17. xg2Ne2 18. Wd3,b4
19. xd3Nf1 20. Ne1,d2
20. xf1Nd1 21. Wa4,e1 x Wa4, Wd1

Your opponent places any marble on d6 or e6 and removes any ring but a4, b5, c6, d7 and f5:
Note that in this case you isolate the two white marbles on the same side of the board.

Your opponent You

15. Nd6/e6,nn 16. Ne6/d6,b4
17. xe6Nb5 18. Nd6,c4
19. xb5Nf6 20. Wf5,g4
21. xf5Nd7 22. Nc6,c5
23. xd7Nb5 24. Wa4,c6 x Wa4, Wb5

Your opponent places any marble on e5 or f5 and removes a4:

Note that in this case you isolate the two white marbles on the same side of the board even though your opponent removed the uttermost corner on that side.

Your opponent You

15. Ne5/f5,a4 16. Wf5/e5,c4
17. xf5Nd5 18. Ne5,d4
19. xd5Nf5 20. Ng4,d5
20. xg4Ne6 21. Wf5,g4
22. xf5Nd7 23. Nc6,c5
24. xd7Nb5 25. Wb4,c6 x Wb4, Wb5

Have fun!

Karina

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