Playa Chess

[curmudgeon]

Something to play around with, even if the person originating this seems to have lost interest. This arose on a thread entitled "Motorized Chess", back on the forbidden board.

Somebody calling himself "Rusted Iron" wrote

Here's the concept:

Electric motor scooters, (the kind you ride standing up), turned into chess pieces, with the playa as our board.

Anyone want to join in?

going on to add, after a few other people had written in, that

Wish I could provide scooters, but I can't do that.

I've considered doing it with bikes, but it doesn't seem right to have the pieces sitting down.

How to make the board? Two ideas:

1) sketch it in the playa... it's temporary anyway.

2) turn the city into a giant board... a bit anarchistic, you have to trust pieces who've been killed to stay dead. Okay, that probably won't work.

to which I responded with another possibility:

3. Revise the rules of the game so that you don't need squares, any more. All you would need would be four posts marking the field of play, for pieces whose positions would be defined as coordinates on a grid aligned with the posts, the coordinates taking on continuous instead of discrete values. One piece of dust is as valid a center for a square as any other, so no need to mark out squares and no colored moop in the dust to deal with after BM2006.

Guessing that somebody probably would have played around with this idea, I did a search under the words "continuous chess" and came across this page on the chessvariants dot com site, which you can find archived in the Internet Archive should the original copy go down.

The rules are set up for an 8" by 8" board, but scaling them up to a larger playing field should be easy. Maybe the biggest change in the rules is that these is no en passant capture. The rule limiting the nearness with which one pieces may approach another without stopping could be enforced by placing circular bumpers around the motorized pieces, with appropriate radii and trip switches temporarily cutting power to a piece on impact.

Two modifications I'd like to toss in ...

Were this game to be run on a computer, the moves suggested by the originator of the chess variant I'm referring to would be easily done. (Picture the board aligned in a standard Cartesian Coordinate system, with the edges running parallel to the axes. The bishop moves as far as the player wishes along lines of slope +1 or -1, the rook moves parallel to one axis or another during a move (as far as the player wishes), queen moves as a rook or bishop, Knight "leaps with a bearing of arctan(0.5), arctan(2), arctan(-0.5) or arctan(-2) up to a distance of sqrt(5)" , "1" meaning 1", or 1/8 of a board length. The King moves orthogonally up a 1/8 of a board lngth or diagonally (along a line of slope +1 or -1) up to sqrt(2)/8 or the board length. The pawn moves parallel to the y-axis, away from the x-axis, up to 1/8 of a board length, capturing other pieces along lines of slope plus or minus one, up to a distance of squrt(2)/8 of a board length, where squrt(2) is the square root of two. Captures are as you'd expect them to be: carried out by moving one's pieces so the enemy piece is within a radius of 1/8 of a board length.

On a computer screen, this is easy, because we're just adding numbers together and keeping track of them. Out on the dirt, this is not as simple because even on the Playa, the ground is not completely level. Irregularities will throw off the direction of travel.

Suggestion: Make a virtue of inescapable necessity. Instead of demanding that pieces travel in precisely the right direction, allow them to deviate from their course by some fixed number of degrees. Then, on arrival, before captures are taken, "scatter the piece" by displacing the piece along a vector determined by some probability distribution, trying this into the "Kismet" theme camp concept that I can't get anybody interested in. Yet.

Having our displacement random vector be a bivariate Gaussian would be a little mean. I'm thinking maybe something of the form [U1,U2], where U1 and U2 are independent, uniformly distributed random variables on the interval (0,L/16), where L is the length of the field. The referee pulls a pair of numbers of a printout of random numbers, scales, tells the player how much to move the piece by along each axis, and then captures are taken. The piece might be thought of as being randomly adjusted in the square that materializes beneath its feet, in a manner of speaking.

Any thoughts?

[Traveller]

Interesting, but I notice that you're a EE person, meaning that moving parts is not what you do. Do you have somebody lined up to handle the mechanic of the moving pieces?

I'd lose the random number printouts, because the referee would probably lose them. I suppose you could put them on a clipboard, but stuff happens on the Playa. One way or the other, paper has a way of getting loose and blowing away. Picture your ref's random numbers being carried off by a dustdevil, while the players look up and go "now what".

What I'd do:

Take my probability distribution, whichever one I wanted to use for the piece scattering, and find the percentiles. Know what a 20-sided die is? You can pick them up in game stores, the fantasy role players use them. I'd get two small bags of them, different colors just to be safe. I'd roll the dice, ignoring the little bars on the bottom that let you tell the difference between 5 and 15, using one of the dice to determine the 10s digit of a number being generated, the other the 1s digit. That's why you want two different colors of dice - so you can tell which is which.

According to the conventional way of reading the results, the number than comes up will be somewhere between 1 and 100, but let's make life easier for ourselves and read "00" as being 0. What you now have can be directly read as a percentile. Let the displacement be that percentile on your probability distribution.

Instead of having a stack of papers the referee has to shuffle through, loosening them from their binder, he can have one table, maybe laminated and encased in acrylic for weight. If you're feeling really ambitious, maybe you can make your own giant sized dice and toss them out on the ground after each move, maybe a little smaller than bowling balls. Adds a little element of theatre to the action. What you'd need to make would be very regular icoshedrons (regular 20-sided polyhedrons).


_________________


(The discussion Curmudgeon is referring to is the Motorized Chess thread on ePlaya).

[deletedbarkeep]

I liked the idea of adding a little random scatter at the end of a move, but no so sure about the uniform distribution stuff. I think that you're losing a layer of strategy right there.

How about giving the player a little control over "where on the square' a piece lands, but not total control. Think of it like somebody's shooting at a target. He can't completely choose where the bullet's going to land, but he has some control and a spot near the bullseye is a lot likelier to get hit than a spot near the edge of the target. That way, the player still has to work the unexpected into his plans, but he's not being blown around by the wind.

Make sense?

[curmudgeon]

admin said:

Interesting, but I notice that you're a EE person, meaning that moving parts is not what you do. Do you have somebody lined up to handle the mechanic of the moving pieces?

Not at present, and you're right, that's a potential show stopper, or at least it would be if I were fixed in my plans. These are just very preliminary discussions in which I toss out an idea, I see who I can get interested and what skills they bring. I'm realistic enough to know that plans will have to change.

There are a lot of mechanics and mechanical engineers who go to Burning Man and to regional burns, and maybe a few of them will read this and get interested enough to want to take part. If not, though, no big deal. Perhaps one might have a grid of electromagnets underlying a relatively slippery surface, along which smaller pieces would be pulled by kicking the magnets on weakly in sequence, the last one kicking on strongly once the piece was in position, so that it would be relatively undisturbed by the passage of other pieces. One would need to cover the set, though, to shield the pieces from the wind and the surface from the dust. It would no longer be an outdoor game.

Or maybe one might dispense with almost all technology aside from maybe a little very simple surveying equipment to lay out the acceptable lines of travel, and just have the players carry the slightly comically oversized pieces, each one a few feet high. I think I like that idea better, and not just because it's a lot less work for me.

I'd lose the random number printouts, because the referee would probably lose them. I suppose you could put them on a clipboard, but stuff happens on the Playa.

OK, point taken. I can already picture somebody water cannoning the referee. "Why are you upset, man?" Percentiles are easily computed, so using those is probably a good eye-saving alternative to dealing with a stack of printouts, and it's better theatre anyway. Thanks.

[curmudgeon]

deletedbarkeep said:

not so sure about the uniform distribution stuff. I think that you're losing a layer of strategy right there.

How about giving the player a little control over "where on the square" piece lands, but not total control. Think of it like somebody's shooting at a target

I suppose. One could use a kind of truncated normal. Picture taking your usual normal density function, with the tails "chopped off" (the usual value of the density replaced by zero once one is a certain number of standard deviations out), the density then being renormalized to produce a new probability density? Or I suppose one could take a normal random variable, and cap it off by applying some function of this form to it:

f(x) = a if x<a, b if x>b, x otherwise

but this leaves us with a pair of large point masses at the endpoints of the support for the density, and I find that ugly.


What I wanted to avoid by not using a bivariate normal random vector for the scatter was the possibility of a piece landing outside of "its square", and maybe even off the board altogether. I suppose, though, if we're going to pursue the "chess as war" metaphor as we dispense with the most visiblly unbattlefield like stylization of the board (the establishment of discrete squares), we could decide that on a roll of 00, the piece "goes awol" and is lost to play. The King, however, would not go awol under any circumstances, because the old guy knows that it's his neck on the chopping block in the end. In this metaphor.

One stylization that I'd like to bring back, though, that was removed in the earlier chessvariants.com version, is the fixed length of the knight's move. I think that ungainly hop is too basic a part of what gives the opening its character. The base move should be what it would be in regular chess, translated to the continuous board, with the player allowed to adjust within the pieces "virtual square" (ie. move up to 1/16 of a board length along each axis of the board) before the random disturbance is included.

I suppose, also, that we could use a relatively low standard deviation for the normal we truncate, so that a serious amount of scattering would become that piece of bad luck one has to plan for.

[observer]

Obligatory gratuitous self-promotion: a page of mine still under construction, on the Apocalyptic Herrings site, where Playa Chess gets tied into a camp concept. Hey, somebody had to do it.

Am I the only one having a "why are we even here" kind of moment? I'll finish putting together that fish site because the notes for it were already written, but why are you guys here? You get lurkers, but do you ever hear from anybody you aren't running into at Kopi, anyway?

I'm all for playing around with this concept, but Burning Man is not the place to do something like this. Have you considered Around the Coyote or some other local arts festival?

[Traveller]

observer said:

Am I the only one having a "why are we even here" kind of moment?

No, you're not.

[curmudgeon]

observer said:

\Have you considered Around the Coyote or some other local arts festival?

You do understand that we'd end up playing a $200 chess game if we did that, right? That's how much ATC charges registrants, and believe it or not that's on the low end for art fair entrance fees in our area. At the Gold Coast Art Fair, I think that the artists said that they were charged $350. I don't know about you, but I can do an awful lot with $350. Even if my finances could stand it, spending that kind of money would feel weird.

One also has to look at space contraints. Wicker Park used to have a lot of empty space in its commons, by cramped Chicago standards, but that's changed. Somebody just had to carve a baseball diamond out of one corner, and between that and the field house, there's not a lot of available dirt left on our little triangular patch of soil. Realistically speaking, I can't picture the theatre curators giving us even a 40 foot square patch.

What one could do is just get a permit to use some space in Lincoln Park, advertise by zine and keep it simple, assuming that one event wanted to stick with the "giant chess piece" concept. Doing it here, I'm not so sure that I would. Surrealism plays better in the otherworldly atmosphere of the desert, I think.