Website founded by
Milan Velimirović
in 2006

13:34 UTC
ISC 2021



Remember me

Forgot your
Click here!
to create your account if you don't already have one.

Rating lists


MatPlus.Net Forum General Another CSE question taken over :-)
You can only view this page!
(1) Posted by Hauke Reddmann [Saturday, Jan 30, 2021 19:29]

Another CSE question taken over :-)

The game starting position is a h#2 (Fool's Mate) if you
either switch the right to move or the party getting mated
(which makes a bit of sense since it is only convention
that Black starts and is mated. But White begins in chess,
so "shortest mate" and "h#?" are different).

A twin is a) add a piece, b) delete a piece, c) swap two
pieces, d) change identity of a piece (and I possibly forgot
a few lesser ones, e) change stipulation isn't relevant here!).

Twin the game starting position such that...
Puzzle A. It's an unique h#2 (White begins and is mated)
Puzzle B. No h#3 is possible (dito)
Ignore legality questions!
I found only 1 (for fuzzy values of 1) solution for both.
But I didn't try the MORE wacky ideas yet.
(Read Only)pid=20554
(2) Posted by Ulrich Voigt [Saturday, Jan 30, 2021 21:57]

Switch wQd1 with bNb8 for a unique h#2: 1. e5 Qxc7 2. Ke7 Qxe5++
(Read Only)pid=20555
(3) Posted by Adrian Storisteanu [Saturday, Jan 30, 2021 23:11]

Another regular h#2 (black starts, gets mated):

SWAP Sb1 <-> Qd8:
1.Sb8-c6 Sd8-e6 2.Sc6-d8 Se6xc7#
(Read Only)pid=20556
(4) Posted by Adrian Storisteanu [Saturday, Jan 30, 2021 23:21]

Interestingly, two possibilities for a correct, regular h#1.5 (white starts, mates):

SWAP Ra1/h1 <-> Bc8:
1...Rc8xc7 2.Qd8-c8 Rc7xc8#

SWAP Pc2 <-> Ph7:
1...Qd1xc2 2.f7-f6 Qc2-g6#
(Read Only)pid=20557
(5) Posted by Adrian Storisteanu [Sunday, Jan 31, 2021 00:28]

Finally, off topic (maybe for an extra credit!?), but had to try it, a series helpmate in 3 (ser-h#3):

SWAP Ra1/h1 <-> Ra8:
1.d7-d5 2.Qd8-d6 3.Sb8-d7 Ra8xc8#
(Read Only)pid=20558
(6) Posted by Ulrich Voigt [Sunday, Jan 31, 2021 00:57]

Swap wNg1 <--> bKe8 and there is no h#3.
(Read Only)pid=20559
(7) Posted by Peter Wong [Sunday, Jan 31, 2021 01:04]
(Read Only)pid=20561
(8) Posted by Siegfried Hornecker [Sunday, Jan 31, 2021 05:06]

Only dual free if pawn double steps aren't allowed (unless I missed other solutions).

Ng1-Ng8 swap, h#2, duplex
1.Nxe2 Qxe2 2.g6 Nf6 mate
1.Nxe7 Qxe7 2.g3 Nf3 mate

(Found by Theodoros Glakatis in the old thread.)

(2) Posted by Theodoros Giakatis [Monday, Jan 1, 2018 21:10]; edited by Theodoros Giakatis [18-01-01]

Happy New Year!!
If I understand the definition correctly, a solution can be:
Changing the position between the White and Black Knights on g1 and g8 can lead to the following
1.Ne7 Qe7 2.g3(g4) Nf3 #.
If someone has played some Caro-Kann games it's easy for him to imagine this image of mate.


(Read Only)pid=20562
(9) Posted by Joost de Heer [Sunday, Jan 31, 2021 10:26]

Solution for a)
Zóltan Laborczy, after John Niemann
Problemesis 2004
(= 16+16+1N )

(Imitator c6)
a) h#3
b) Ic6->g6, h#3 2.1.1...
c) Ic6-e4, h#3
d) Ic6->d7, h#3
e) Ic6->d8, h#4
f) Ic6->b2, h#2.5
g) Ic6->b1, h#2.5
(Read Only)pid=20563
(10) Posted by Hauke Reddmann [Sunday, Jan 31, 2021 12:50]

Oh, I already posted (half of) it? So much for my
computer memory...
My own solutions were
a) Ph7->b3 or d3 (C+) (i.e. essentially Adrian's)
b) swap Bf8 with any White "heavy" (C+) (i.e.
an addition to Ulrich's)
(Read Only)pid=20565

No more posts

MatPlus.Net Forum General Another CSE question taken over :-)