The king base diameter USCF/FIDE guideline doesn't make any sense?

I've read in a lot of places that the king base diameter should be around 72-75% of the square size. According to USCF and FIDE. I also read that Europeans tend to favor less space than the USA.

However, here in Western Europe (The Netherlands) the king base diameter seems to be more around 68%! I see this in tournaments and clubs. The standard amateur tournament set with the plastic folding board and the plastic pieces has a king base diameter of 68% for sure. Also the pawns fit easily with 4 pawns on a square. Here these sets are always provided at tournaments by the organizers. 

Even the DGT set you see in the big tournaments seems quite spacy? 

In the following picture the official 1950 Olympiad Dubrovnik chess pieces has a king base diameter of 39mm on 2.375 (60mm) inch squares

https://www.noj.si/uploads/Image/Dubrovnik%201950/Novica%201.jpg

So conclusion:

- Standard Western European Tournament and club sets have a low king base diameter of around 68%

- DGT tournament set has low king base diameter (can anyone confirm this?)

- Official 1950 Chess Olympiad has a low king base diameter

So why do the official guidelines from USCF/FIDE don't hold up with reality? 

There were quite some topics in the past about correct and incorrect scaling. So some people care and like to discuss about it. And obviously I care, otherwise I wouldn't make this topic.

You don't HAVE to reply by the way of the topic doesn't interest you. 

FIDE is very flexible in this question, here is complete guideline:

https://www.fide.com/FIDE/handbook/Standards_of_Chess_Equipment_and_tournament_venue.pdf

The King base diameter is only one measurement of a set.  The top body size of the piece will also matter in how the pieces or set look on the square size board.  You will notice the rules state that it is about that percentage, not exactly.

If you look at Jaques pieces, you will see they have wider bases than other sets like the Lardy for instance.  The wider base will need to be a higher percentage of the square size than a narrower base.  In both sets the body of the pieces will look better on the same size square even though one set’s King base will be a higher percentage than the other.

hess Set Sizing - Pieces vs Board...

The primary sizing criteria for the set and board is that of square size vs King base diameter...
A good rule of thumb is...
King base diameter = 0.75 * square size
or equivalently....
Square size = 1.33 * King base diameter
Any variation from these ratios, or the size of individual pieces and pawns is a matter of personal preference...

http://blog.chesshouse.com/how-to-select-the-right-size-chessboard-for-pieces/

THE OVERLOOKED FACTOR

Seems like everyone is basing their selection of a chessboard based solely on the dimensions of the king, but what about the pawns? They represent half of all the pieces on the chessboard. It's worth considering.

Four pawns to the square. Yeah, right!

Ah, but that's all ancient history you say. Well, take a look at this from the 2016 Sinquefield Cup.

How ridiculous would any of these boards be with the pawns scaled down to 'four-pawns-to-the-square'? It's a mid-19th aesthetic that's been kept on life support because of the popularity of the 1848 Staunton chess set.

Second to last picture can be four pawns on a square

But you are right. Those old soviet sets and in those days setups were more cramped compared to nowadays tournaments with the DGT boards with the timeless pieces.

The latest FIDE regulations state that the diameter of the king should be between 73-78% the size of the square. Well, how then do you account for the FIDE approved Championship chess set -- a 39mm diameter king designed to play on a FIDE approved 55mm DGT e-board (see pic below)? That works to a king diameter of only 70.9%, with the diameter of the pawns, instead of the recommended 4 pawns to the square (50%), coming in at 54.5% of the square! So why should we be so concerned about regulations that FIDE itself doesn't adhere to?

Now FIDE is faced with a dilemma, either change the Championship Chess Set to adhere to the regs, or change the regs to accommodate the the chess set.

I agree with you 100%. 

Hi Duvupov, 

I asked a very VERY similar question about 5 weeks ago, and I like the 0.72 to 0.76 (Don't quote me please!) and I find it very pleasing.   I know that in Europe the BASE of the pieces are much more crowded and a tighter fit with less "breathing room" on the board.   To me (IMHO) this was not my ideal size.

To be honest, I asked the question because I really didn't have a BASELINE nor understanding of the piece size when compare to the square size of the board.  You can believe that *MANY* members here on this forum were kind enough to point me in the right directly and finally I chose a setting that worked for me.

I don't play in tournaments at all and just enjoy a casual game here and there and really wanted to get the best size Chess Set(s) to match the Chess boards in my collection (don't ask...  LOL).

Since it's not tournament based, I just decided to find a style (Staunton) and Diameter ratio that was pleasing to my US/American eyes and IMHO that was the 0.72 ~ 0.76 diameter size for my 2.25" and 2.5" board.

Bottom line, unless you're in tournament, it all only boils down to what is pleasing to you..!  

lonewolf69ay,

My sweet spot is 76.5%, and here's why:

https://www.chess.com/forum/view/chess-equipment/a-system-for-sizing-chess-pieces-and-boards-long

Where is the line between stretching the regs and breaking them? The following is from the latest FIDE regs dated 2017.

"Recommended height of the pieces is as follows: King – 9.5 cm, Queen – 8.5 cm, Bishop – 7 cm, Knight – 6 cm, Rook – 5.5 cm and Pawn – 5 cm. The diameter of the piece's base should measure 40-50% of its height. These dimensions may differ up to 10% from the above recommendation, but the order (e.g. King is higher than Queen, etc.) must be kept."

Now, let's look at how these dimensions apply to the FIDE Championship chess set. After all, the set was designed to their specifications.

Oops! Looks like six out of eight back-row pieces are way too tall, even beyond their 10% fudge factor. So, outside of tournament play, why should we adhere to regulations the issuing body doesn't observe?

Reminds me of the classic parental admonishment, "Do as I say, not as I do!" And my childlike response is, "Why?"

These are just recommendations that help the FIDE arbiter make a decision if someone complains about the chess set in FIDE event.