After 35 years of tournament play I got around to studying regulations for allowable chess sets in rated play. Looking to buy one more set to take to tournaments, preferably triple-weighted.
Seems most rated games are played with non-standard equipment. Who knew? The standard for the size of squares on the chessboard is the old .78 formula trick. (You see .75 and .80 mentioned other places but the Rulebook says .78.) That’s the ratio of the base of the King to the size of the square.
So, since most standard tournament sets advertise a King height of 3.75" with a 1.5" base diameter, that means the squares on the board should be 1.92". Let’s round it to 2" using the .75 ratio, just for fun.
The Rulebook says squares may not be smaller than the formula suggests, but may be up to 1/8 of an inch larger. Here lies the problem. The most common square size on chessboards advertised as tournament equipment is 2.25". That includes boards that are bundled with chess sets for combined purchase.
That makes the squares a full 1/4 inch too large, or 0.3269" to be precise.
Go figure. I guess the reason I have never heard a player complain the squares were too big for the pieces is the same reason I never complained of it. Bigger squares you can deal with, but when the pieces are too big for the board squares there is no way to adjust. Been there a few times.
Now if I could find a deal on a decent board with 2" squares I could finally start to follow the rules after three and a half decades of non-compliance…
In Canada, I played on plastic boards with 2" squares and Club Special sets. It looked very crammed. The pieces seemed too tall and not in proportion to the board. Since the organizer provided all of the sets, boards, and clocks, that is what we played with. It took a while to get adjusted to it. I was always afraid I might knock over one of the “tall” pieces when I reached for them. As I recall, the boards were made in England, so I imagine there would be the same adjustment problems when playing in European tournaments.
One year in the class D section of the Illinois Class, I saw a game being played on a peg-in set with a board about 7 inches square. Their clock? An old Garde, basically a grandfather clock, about 9 inches wide. The clock was larger than the board. The incongruity made me burst out laughing.
When the Fischer boom got started, many players new to tournament play brought Renaissance style chess sets or some other non-Staunton type of set to competitions. It was common to see several of these sets in use. The Club Special or Player’s Choice sets, with cheap, single-weighted, solid plastic pieces were years away from being popular in tournament play. In the Pittsburgh area, many players had the Drueke set, with cream and black color pieces, or used a wooden set. Then the Cavalier set became popular with its tall kings. By the 90’s, the Ultimate Chess Set, with stubby mushroom-like pawns became the thing. The Pittsburgh Chess Club has a number of these latter style sets in use. All of the old Drueke sets that they used to use as a standard for tournament play are in a big box. Many of the pieces lost their weights when the glue dried out and the constant banging of pieces loosened the metal weights inside.
At one time, someone in the Pittsburgh Chess Club purchased over a hundred heavy paperchess boards that had 2.25" squares. He had them heavily laminated. Board numbers were put on each board. For many years these boards were laid out for use in tournaments. Players only had to bring chess sets to a tournament. They left their wooden and vinyl boards at home. These boards are in a big carton in the club, but I rarely see these boards used anymore. A bunch of vinyl boards, some of them scratched, are used for casual play and tournaments now.
While my OP was driven by insomnia and an unsuccessful attempt to fight it off by reading the 6th Edition, it is kinda amusing that most board/set combos used at tournaments and offered for sale do not conform to the standards outlined in the rulebook.
I ordered a triple-weighted plastic set with a green vinyl board combo from Amazon for $25. Supposedly this is a higher-quality board that will lie flat and not tear, but we shall see. Next time I toss money at chess equipment I might try a silicone board.
The King is 3.75" tall with 1.5" base. The board is 20" x 20" with 2.25" squares. Totally typical—but not in compliance with rulebook standards. Oh, the shame.
I know people who love the silicone boards. When I have touched the surface of the boards, they creep me out. Like touching the skin of a hairless mole rat. Don’t ask.
BTW, does anyone know when 3.75" king height became the de facto standard?
I have several sets from the 1983 US Open in Pasadena (they sold them off very cheap after the tournament, so I picked up a bunch for the Caltech chess club). They king height was 3.625, with a base of 1.5.
My Drueke Player’s Choice set from the same time period also has a 3.625" king, with a 1.625 base.
The take-away from this is that there is a range of King heights and bases, as well as square sizes for each, that are acceptable.
Note that the 78% is an “around” percentage. In the last sentence they say a King base of 1 3/4 inch would work well on a 2 3/8" square size. That is a little under 74%.
Also note that the base size is not the only determinate of whether a piece or set fits a specific square size well. The other dimensions of the pieces also matter.
And the rule is written as a description of what the author or authors have seen work. It is a guideline not a dictation of size and percentages.
If it were a dictation then it would list and only allow specific sizes in tournament play.
My OP was tongue-cheeky to the point I almost deleted it, (it read much more amusing in the wee hours…) but the more I look at equipment standards the more I chuckle over how a majority of rated games are played with equipment that does not meet rulebook standards, be they informal guidelines or mandates or something in between.
I plan to take my new set/board to a weekend Swiss in July. Maybe I will ask a few fellow patzers what they think about all this.
Note that they say it would work well on 2 1/4" to 2 3/8", which is a range of 1/8", so I would assume they are using 78% (which gives 2 1/4" if we round to nearest 1/8th), and then got to 2 3/8" applying the rule that you can go up to 1/8" higher.
74% would give 2 3/8" to 2 1/2" as the good range.
I mentioned my old Drueke Player’s Choice pieces from the '80s in an earlier post in this thread. For those who miss that set, I’ve found a currently produced set that is fairly close: the Chess USA 61-206 set.
Here is an album with a picture of the white pieces from the two sets interleaved: http://imgur.com/a/ntXFu. The Drueke pieces are on the right in each pairing.
The album also contains a close up of the top of the queens showing the differences in their crowns, and a close up of the knights showing the differences in detail. In addition to those differences, the 61-206 king is 3 3/4", which is 1/8" taller than the Drueke king, the Drueke king is heavier (~56 g vs. ~45 g), the Drueke rooks and minor pieces are about 15% heavier than the 61-206 versions, the Drueke pawns all weigh 21 g, whereas the 61-206 pawns vary from 20-23 g, and the 61-206 bishop slot is fully cut out, whereas the the Drueke slot is really just a shallow groove.
The color is spot on.
The 61-206 is close enough to the Player’s Choice that if you’ve got a Player’s Choice that you retired due to lost pawns, you could replace the missing pawns with 61-206 pawns and your opponents would almost certainly not even suspect you had mixed two sets.
If you are missing something else, you could probably still get away with replacing it from the 61-206 as long as you replaced all pieces of that type. For instance, if you lost a white Drueke bishop, and just replaced that one bishop, people might notice, but if you replaced both white bishops that would probably work (and if you also replaced the black bishops, it would be the perfect crime).
I do hope all this talk about 78% refers to linear dimensions (height and width of square, and diameter of king’s base) and not area.
The area of a circle inscribed fully in a square is almost exactly 78% of the area of the square (pi/4 to be exact) which would mean that the king would barely fit onto the square.
No wonder there’s a rule prohibiting the two kings from being on adjoining squares.
And most rated games are played at 66.67%. Chess players are rebels. This assumes we trust the makers of chess sets and boards to provide accurate measurements for their products. Hmmm.
Their scrunch-ability is nice, but felt-bottomed pieces refuse to SLIDE across the silicone mat chess boards. I cannot live with that limitation, so I put my $ money back in my pocket.
