[vchess.git] / client / src / translations / rules / Upsidedown / en.pug

p.boxed
  | Pawns start on the 7th rank. Move a knight to promote them.

p.
  ...Only the initial position changes, but this makes a huge difference.
  In particular, castling would be rather pointless so it's disabled here.
  En-passant captures are impossible because all pawns already reached 7th rank.

h3 About the initial position

p.
  Since truly random start can allow a mate in 3 with a knight,
  the kings have at least one knight neighbor in the initial position.
  This allows to move free out of potential check from the very beginning.

p.
  A less constraining condition would be to require the two knights to stand on
  two squares of different colors, but it's not enough as proved by the
  following diagram.
  White can mate in 3: 1.Nc6 followed by Nb4 threatening both a2 and d3.

figure.diagram-container
  .diagram
    | fen:RBN1BRRQ/PPPPPPP/8/4n3/8/8/Nppppppp/brkbqr1n:
  figcaption After 1.Nc6 Nf3 2.Nb4 Ne5 (covers d3 but not a2) 3.Nxa2#

h3 Source

p
  | See for example the 
  a(href="https://www.chessvariants.com/diffsetup.dir/upside.html") Upside down chess
  | &nbsp;page on chessvariants.com.
Commit	Line	Data
dbcc32e9	1	p.boxed
7dc18cbe	2	\| Pawns start on the 7th rank. Move a knight to promote them.
dbcc32e9	3
dbcc32e9	4	p.
7dc18cbe BA	5	...Only the initial position changes, but this makes a huge difference.
	6	In particular, castling would be rather pointless so it's disabled here.
	7	En-passant captures are impossible because all pawns already reached 7th rank.
dbcc32e9	8
69f3d801	9	h3 About the initial position
dbcc32e9 BA	10
dbcc32e9 BA	11	p.
7dc18cbe BA	12	Since truly random start can allow a mate in 3 with a knight,
	13	the kings have at least one knight neighbor in the initial position.
	14	This allows to move free out of potential check from the very beginning.
dbcc32e9	15
5915f720	16	p.
7dc18cbe BA	17	A less constraining condition would be to require the two knights to stand on
	18	two squares of different colors, but it's not enough as proved by the
	19	following diagram.
	20	White can mate in 3: 1.Nc6 followed by Nb4 threatening both a2 and d3.
5915f720	21
dbcc32e9	22	figure.diagram-container
7dc18cbe BA	23	.diagram
	24	\| fen:RBN1BRRQ/PPPPPPP/8/4n3/8/8/Nppppppp/brkbqr1n:
	25	figcaption After 1.Nc6 Nf3 2.Nb4 Ne5 (covers d3 but not a2) 3.Nxa2#
dbcc32e9 BA	26
	27	h3 Source
	28
	29	p
7dc18cbe BA	30	\| See for example the
	31	a(href="https://www.chessvariants.com/diffsetup.dir/upside.html") Upside down chess
	32	\|  page on chessvariants.com.