Which diagonals have names?

So far I've seen a name for only one of the diagonals on the chessboard: the "Italian diagonal," which runs through f7 from a2-g8, probably named after the Italian Game opening, where White's king bishop uses that diagonal.

http://exeterchessclub.org.uk/content/italian-game-beginners

http://franosch.org/chess/italian.pdf

Does anybody here know of any other diagonals with names? It seems to me another important diagonal for White's tactics would be the diagonal that runs to h7, which is a common spot for a bishop sacrifice from White.

OK, so it seems only one diagonal has an official name, so let's move on to step 2, where we invent names for the remaining, nameless diagonals. Who wants to show off their knowledge and/or creativity?

I came up with the following ideas, mostly based on openings that use those diagonals, but I'm getting stuck since I don't know enough openings and which diagonals they use to fill in the rest. Also, I'm not particularly happy with some of my names.

ending squares, all squares, # of squares, English name:

a8-a8     a8                        1 (a single square)
a6-c8     a6-b7-c8                  3
a4-e8     a4-b5-c6-d7-e8            5                     "Spanish Diagonal"
a2-g8     a2-b3-c4-d5-e6-f7-g8      7                     Italian Diagonal
b1-h7     b1-c2-d3-e4-f5-g6-h7      7
d1-h5     d1-e2-f3-g4-h5            5
f1-h3     f1-g2-h3                  3
h1-h1     h1                        1 (a single square)

a7-b8     a7-b8                     2
a5-d8     a5-b6-c7-d8               4                     "Caro-Kann Diagonal"
a3-f8     a3-b4-c5-d6-e7-f8         6
a1-h8     a1-b2-c3-d4-e5-f6-g7-h8   8 (a long diagonal)   "Larsen Diagonal"
c1-h6     c1-d2-e3-f4-g5-h6         6
e1-h4     e1-f2-g3-h4               4                     "Fool's Mate Diagonal"
g1-h2     g1-h2                     2

g8-h7     g8-h7                     2
e8-h5     e8-f7-g6-h5               4                     "Scholar's Mate Diagonal"
c8-h3     c8-d7-e6-f5-g4-h3         6
a8-h1     a8-b7-c6-d5-e4-f3-g2-h1   8 (a long diagonal)   "Hungarian Diagonal"
a6-f1     a6-b5-c4-d3-e2-f1         6
a4-d1     a4-b3-c2-d1               4                     "Rubinstein Diagonal"
a2-b1     a2-b1                     2

a1-a1     a1                        1 (a single square)
a3-c1     a3-b2-c1                  3
a5-e1     a5-b4-c3-d2-e1            5                     "Bogo-Indian Diagonal"
a7-g1     a7-b6-c5-d4-e3-f2-g1      7
b8-h2     b8-c7-d6-e5-f4-g3-h2      7
d8-h4     d8-e7-f6-g5-h4            5
f8-h6     f8-g7-h6                  3
h8-h8     h8                        1 (a single square)

DERIVATION OF ORIGINAL NAMES (alphabetical)

"Bogo-Indian Diagonal": diagonal where Black checks in the Bogo-Indian: 1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+
"Caro-Kann Diagonal": diagonal along which Black's queen often attacks in the Caro-Kann
"Fool's Mate Diagonal": diagonal on which White is mated in Fool's Mate: 1. f3 e5 2. g4 Qh4#
"Hungarian Diagonal": diagonal covered in the Hungarian Opening (Benko's Opening): 1. g3
Italian Diagonal: diagonal covered in the Italian Game: 1. e4 e5 2. Nf3 Nc6 3. Bc4
"Larsen Diagonal": diagonal covered in the Nimzovich-Larsen Attack: 1. b3
"Rubinstein Diagonal": diagonal along which White's queen moves in the Rubinstein Caro-Kann
"Scholar's Mate Diagonal": diagonal of mate in Scholar's Mate: 1. e4 e5 2. Qh5 Nc6 3. Bc4 Nf6 4. Qxf7#
"Spanish Diagonal": diagonal of the pin in Ruy Lopez (Spanish Opening): 1. e4 e5 2. Nf3 Nc6 3. Bb5

I call this one "snippy."

Intriguing names, but how about supplying a justification for each one?

Sorry, but it's hard to think with "snippy" pointing down "there".

I had to look up that opening. I like that name better than my Caro-Kann name so I'll call that diagonal the Cambridge Diagonal. Thanks. Any more ideas? The b1-h7 is where the classic bishop sacrifice occurs, Bxh7+, but I don't know which openings give rise to that sacrifice. Does somebody here know?

Anything wrong with long diagonals?

Yes, the same thing as is wrong with knights: there are two of them. They need to be distinguished.

Black long diagonal. White long diagonal.

Ta Daaa!

Queen knight. King knight.

Ta Daaa!

Now about those other diagonals...

Easier to remember them for what they do. In the starting position:

Diagonals that connect to queens give checks.
Diagonals that connect to bishops pin knights or prevent castling.
Diagonals that connect to knights attack a castled king.
Diagonals that connect to rooks influence the center.

DTCTQGC = Diagonals that connect to queens give checks.
DTCTBPKOPC = Diagonals that connect to bishops pin knights or prevent castling.
DTCTKAACK = Diagonals that connect to knights attack a castled king.
DTCTRITC = Diagonals that connect to rooks influence the center.

Nope, it just doesn't seem to roll of the tongue nicely.

More seriously, that's a pretty good way of categorizing diagonals into at least four categories: by function. I was also wondering about naming diagonals based on and used by "extended fianchettoes" where the bishop goes out to R3 instead of N2.

Here's what I have so far....

a8-a8     a8                        1 (a single square)
a6-c8     a6-b7-c8                  3
a4-e8     a4-b5-c6-d7-e8            5                     "Spanish Diagonal"
a2-g8     a2-b3-c4-d5-e6-f7-g8      7                     Italian Diagonal
b1-h7     b1-c2-d3-e4-f5-g6-h7      7                     "Classic Diagonal"
d1-h5     d1-e2-f3-g4-h5            5                     "Vienna Diagonal"
f1-h3     f1-g2-h3                  3
h1-h1     h1                        1 (a single square)

a7-b8     a7-b8                     2
a5-d8     a5-b6-c7-d8               4                     "Cambridge Diagonal"
a3-f8     a3-b4-c5-d6-e7-f8         6
a1-h8     a1-b2-c3-d4-e5-f6-g7-h8   8 (a long diagonal)   "Larsen Diagonal"
c1-h6     c1-d2-e3-f4-g5-h6         6
e1-h4     e1-f2-g3-h4               4                     "Fool's Mate Diagonal"
g1-h2     g1-h2                     2

g8-h7     g8-h7                     2
e8-h5     e8-f7-g6-h5               4                     "Scholar's Mate Diagonal"
c8-h3     c8-d7-e6-f5-g4-h3         6
a8-h1     a8-b7-c6-d5-e4-f3-g2-h1   8 (a long diagonal)   "Hungarian Diagonal"
a6-f1     a6-b5-c4-d3-e2-f1         6
a4-d1     a4-b3-c2-d1               4                     "Rubinstein Diagonal"
a2-b1     a2-b1                     2

a1-a1     a1                        1 (a single square)
a3-c1     a3-b2-c1                  3
a5-e1     a5-b4-c3-d2-e1            5                     "Bogo-Indian Diagonal"
a7-g1     a7-b6-c5-d4-e3-f2-g1      7
b8-h2     b8-c7-d6-e5-f4-g3-h2      7
d8-h4     d8-e7-f6-g5-h4            5
f8-h6     f8-g7-h6                  3
h8-h8     h8                        1 (a single square)

If I had to memorize the names I'd probably forget them in a week, but remembering their function lasts a very long time.

You seem very interested in giving things names. If it's just for the sake of naming, then I'm not sure what to suggest.

On the theoretical side of it all, while I admit language is a very powerful tool that aids our thinking, there is also the effect of verbal overshadowing. Later you may have pigeon-holed your thinking into e.g. "The Italian attack maneuver" instead of using ideas fluidly to evaluate a position. (Although typing out each diagonal like that and looking up openings is probably making you much more familiar with the board and openings in general.)

Diagonals pointing from white's kingside to black's queenside are named for the sum of the alphanumeric values.  Thus, the main light diagonal is number 9.  Diagonals pointing from white's queenside to black's kingside intersect diagonals of the other slant with the same number on the d-file, and have the same value as the rank on the h-file.  The main dark diagonal is number 8.  The diagonals through d4 should be described as "8 left" and "8 right" referencing the forward movement of a bishop.

The h5-e8 diagonal goes from black's kingside to black's kingside. What about it?

ghostofmaroczy,

Interesting, but did you make that up, or is that an official system used somewhere?

leiph18,

In answer to your last question to me: Chunks.

People think in terms of chunks, not in terms of numbers or lists of squares. Whenever I see something like "h5-e8", my mind absolutely fails to pull up any associated image immediately, which then forces me to go through the time-consuming procedure of first visualizing where those squares are, then visualizing the diagonal connecting them, but if somebody wrote "Scholar's Mate Diagonal" I would visualize it immediately and I would also have several associations such as: kingside,  Black getting slaughtered in a 4-move mate, dangerous in Damiano's Defense mate, etc.

Ok, seems good.

Playing games also helps. If you get killed on the b1-h7 diagonal, you may not have named it but it's going to stick in your memory :p

What Diagonals were you killed on?

h=8

e=5

8+5=13

5+8=13

Diagonal h5-e8 is number 13.