Commit | Line | Data |
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90e814b6 BA |
1 | p.boxed |
2 | | Pawns start on the 7th rank. Move a knight to promote them. | |
3 | ||
4 | p. | |
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. | |
8 | ||
9 | h3 About the initial position | |
10 | ||
11 | p. | |
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. | |
15 | ||
16 | p. | |
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. | |
21 | ||
22 | figure.diagram-container | |
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# | |
26 | ||
27 | p Note: in the standard initial position, kings and knights are not neighbors. | |
28 | ||
29 | h3 Source | |
30 | ||
31 | p | |
32 | | See for example the | |
33 | a(href="https://www.chessvariants.com/diffsetup.dir/upside.html") Upside down chess | |
34 | | page on chessvariants.com. |