(Online GIPF Puzzle Contest)
Puzzle 6 has more than one solution. White
wins with 6 moves!
White cannot prevent Black from recycling
pieces. The idea behind this puzzle was to make Black recycle
only 3 pieces (i.e. a row including his GIPF-piece) , to leave
White a win with 6 moves (i.e. he'll need 5 moves to make Black
use his last piece, plus one move to confront Black with the fact
that he can't play).
The solution was 1.f7. But that appeared
not to be the only solution: 1.i3-f6 is also a sure win
in 6 moves. I know that I went through that possibility (the complete
sequence of 6 moves), but I must have been confused about something,
because I recall that it counted 7 moves. A matter of stupidity.
But, it's worse! Even if I had counted the right number of moves
following i3-f6, there even appeared to be a third win:
1.i3-f3. I also went through this when checking the puzzle,
and I completely missed this one; I hadn't seen White's second
Possibility 1: f7
Black had 2 possibilities to make sure to recycle pieces with
only 2 moves: 1.d1-d4 and i3-f6. All other possibilities
could be countered or would make him lose his GIPF.
Through playing 1.f7 (see diagram), White reduced Black's
options to one: he may not play 1
i3-f6 any more because
of White's 2.f8-f4. Black would be able to recycle pieces
on the a5-i1 diagonal and on the g1-g6 line, but both possibilities
leave White a simple win with 3.f8-f3:xGf3.
So, Black must play 1
d1-d4. White defends the piece
on d6 with 2.c1-e3, knowing that Black can't capture on
the c1-i3 line without losing his GIPF. Again Black has no option
and plays 2
i3-f6. Because of the piece on f7
White can capture with (3) f8-f4;x and put pressure on
Black's GIPF at the same time. Black, having recycled only 3 pieces,
must defend Gf4 with either 3
g7-e7 or h6-e6.
The first possibility solves nothing, because White simply re-established
the same attack with 4.g7-d6. So, he chooses 3
White can't attack Gf4 with only one move, so he must look
for a way to make Black run out of pieces. No problem because,
because Black has only 2 pieces left.
Possibility 2: i3-f6
1. i3-f6 / h5;x
2. i4-f4;x / i2-g4
Black can't make a row without including g4 or h3
Possibility 3: i3-f3
1. i3-f3 / i3-f6
2. i3-e3 / h5;x
3. g1-g5;x / i2-g4
4. f7 / d1-d4
5. f8-f4;x / d1-d5;x
I don't exclude that there might be even a fourth
solution, but I must confess that I'm kind of GIPF-blind for the
moment. Please send us your solution if it matches a win for White
in 6 moves.
Ad Rovers came up with a 4th solution: h1-f3.
That move makes that Black loses the possibility to play 1...d1-d4.
It leaves him no other choice then 1...i3-f6. White plays 2.f7,
which leaves him an finish similar to solution 1 (see above).
Note: let us know if you find another win for
White with 6 moves!