## Monday, October 02, 2006

### Sticks and Stones: The Mechanic of Sudden Death

Sticks

Way back in the days when kids had wholesome freckles, wore overalls, and carried slingshots made from a forked stick and a rubber band, the starting team in a street game was decided by throwing a stick up into the air.

One player threw the stick and caught it somewhere in the middle with his hand. He gripped the stick with fist. The designated player from the other team then grabbed the stick with his fist right above where the first one was holding it. The first player placed his other hand on top of the second player's fist, and so on until the last person who was able to grab the stick won the right to go first for his team.

The winner was predetermined from the time the stick was caught. All you really had to do was measure the size of the extended part of the stick and divide it by the size of a fist. That's how many fists were going to fit onto the stick, and that's all you really needed to know. Of course, that way is both slower, and less fun.

Today, we can see this mechanic repeated in various forms in numerous games. Go is a perfect example.

In Go, you may find yourself in a position where you can add a stone to your own group which extends the liberties of the group by one. Your opponent can then reduce your liberties by one by placing his own stone. You can then place another stone, again extending the liberties by one. If this pattern continues toward a blank wall, the conclusion is foregone; you are going to lose your group. However, if the pattern is extending to another one of your groups, the extending group may be saved if both groups can be solidified. A wise opponent will work to ensure that these two groups can never meet.

Another game that uses this mechanic is Gipf. There are, of course, others, such as Through the Desert, Othello, and so on.

Stones

I played my first game of Gipf on Sunday with Tal, and I was pleasantly surprised. For some reason, I was expecting the game to be rather like Pente, and therefore a pedestrian sort of abstract game. It also looked a little like Abalone, a wholly mediocre sort of abstract game. However, it turns out to be quite interesting, at least on first play.

In Gipf, you slide stones from off the board into the hexagonal area, stopping at any empty space. You may also land on an occupied space, pushing all stones in a line the same direction for no more than one space. You may not push any stones off the board in this way.

When you have four in a row, you remove these stones and any others in a contiguous line with them off the board. Your stones return to your store, while your opponent's stones are removed from the game. You lose the game when you must place a stone and have none left in your own store.

Like the two other games in the Gipf series that I have played (Yinsh and Dvonn), the game has simple rules yet creates a wonderfully complex game space.

Here are some things you have to think about, all of which I discovered after only one play.

- Having more pieces on the board gives one more control, but also leaves one closer to sudden death, which occurs if you have no stones left to play.

- If you are running low on stones, you can, if possible, remove your own stones from the board simply in order to have more to play.

- It is possible to create double threats, and just as possible to have the board shift in an unexpected direction before you can complete either of them.

- What one person undoes, another person can redo, up until a certain point.

It is this last point that creates the "stick" mechanic that I noted at the start of this post. One person can push one of your stones out of place, whereupon you can push it right back into place. They can push it right back out of place, and so on, until the line cannot be pushed because to do so would require a piece to be pushed off the board. That tit-for-tat ends in sudden death. The last person to move suddenly wins that battle.

Since this can all be calculated from a given position, you need to have a good reason to start this line of action if the end result isn't going to end up in your favor. Very nice.

I have only two negative things to say about the game from my first impression. The first is that, unlike Dvonn and Yinsh, the rich appear to get richer. That is, it looks hard to come back from a losing position, unlike the other two games.

The second is that the box is inexplicably larger than the boxes of the other two games and therefore doesn't stack properly on my shelf.

And by the way, I won the game against Tal, who essentially stopped trying to win about halfway through the game. We then played Oh Hell, and I won at that, too, although it was only apparent during the last three rounds of the game.

Meanwhile, I finished reading the excellent "Greatest Games of All Time" and I'm working on "A Theory of Fun". I'll report on both of them later.

Yehuda