Sorry for the author, who would have deserved the presence of the "Greffier en Chef", holding the post and a true amateur of all these things even when they are difficult.

*Note from the virtual greffier: from the description given, Pachl's problem seems to be corresponding to it *

### 7 - h#2 Take&Make b)Pe5->c4 c)Pb5->f5

neutral Rd1 CAg3 Zf1 Nh2
black Be4f8 Kd5 Pb7c7a5e5c3g6g4h4 Sb8a6 Rh7 Zd4
white Pb5 Kg8

**h‡2 (2+15+4) C+**

b) Pé5->ç4

c) pb5->f5

Take & Make

f1: neutral Zebra (bonder (2,3))

g3: neutral Camel (bonder (1,3))

d1: neutral Rook

h2: neutral Nightrider

d4: Zebra

(a little reminder: the knight is a bonder (1,2))

{Indeed, there is enough to drop the pen, especially when one knows the richness of the Take&Make !

Little help: three black pieces can go to c5 and the Zebra to d4 can be captured in 4 different ways

by a neutral piece which will have to make a Zebra move afterwards, but BRxd4 would be a weakening}

{

}a)
{

} 1.Sa6-c5 nNh2*d4-g2 + 2.nZf1-d4 nCAg3*d4-a6 #
{

}b) bPe5-->c4
{

} 1.c7-c5 nZf1*d4-g2 + 2.nCAg3-d4 nNh2*d4-c7 #
{

}c) wPb5-->f5
{

} 1.Bf8-c5 nCAg3*d4-b1 + 2.nNh2-d4 nZf1*d4-f8 #

Finally, as an introduction to the course, we had an extraordinary presentation involving different types of retrograde analysis.

When you explain these different types, it seems a bit artificial (even very artificial!) and the simple theoretical presentation makes you think about what life must have been like for flies in some English denominational orphanages....

The great Turnbull provided the material and the master explained it to us. Quite luminous presentation !

The Master wrote about it in his report, but the reader will have to hold on if he really wants to follow, proof that when the subject is difficult, ** the oral presentation is superior to the written explanation**. For the same reason, I will not go into it either, except for the simplest example which I will try to develop a little more..

Growing Men. Whites play and mate in 5 moves.

** We have already seen the Growing Men.

A piece cannot play a move shorter than its previous move..

This means that as soon as a piece has played a move of geometrical length n, all its subsequent moves must have at least this length..

** The length of a move is determined by measuring the distance between the centres of the start and finish squares..

A K therefore makes moves of length 1 (when it makes an orthogonal move) or 1.4 (root of 2, when it makes a diagonal move).

The Knights are not directly impacted by this rule, as all their movements have the same length (root of 5, i.e. about 2.24)..

** When we are interested in the moves played previously (retrograde analysis) we will apply the following principle : All moves that cannot be shown to be prohibited are allowed.

In the case of Growing Men (it would be more precise to say "non-shrinking"), a K or a P will have the right to play a move of length 1, unless the contrary can be demonstrated.

### 8 - #5 Growing Men

white Se2 Kf5
black Ph6g5h4h3g3 Kh5

**#5**

Growing Men
{(Apparently) obvious solution :}
1.Se2-d4 ! { threatening } threat: 2.Sd4-e6 ! {et} threat: 3.Se6-g7 #
{It seems that in such a simple position, the Bs cannot do much. But therein lies the genius of Turnbull.
The B's really have the 3 moves g2, h2 and g4 because we cannot prove the impossibility of any of these moves.
** g2 is of no interest in the face of the aforementioned threat.
** h2. Here is indeed a good idea of defence: free h3 to play h4-h3 and give a square to K.
Alas, after } 1...h3-h2 {which is legal !, we can affirm that the Ph3 has played ONLY moves of length 1 (since we are in enlarging chess and he has just played a move of length 1).
-- So it comes from h7.
-- But then h4 comes from another column. So h4 has already played a move of length 1,4.
-- But then h4 is not allowed to go to h3.
AND THEREFORE the W's always checkmate by Ne6 and Ng7#..
** } 1...g5-g4!
{This is a very nice move. It is indeed:
-- We can't prove that g5-g4 is illegal, so the B's can play it.
-- But then, g5 comes from g7.
-- But then, h6 can only physically come from h7!
-- But then, g3 and h3 come from other columns than g and h!
-- So g3 and h3 are not allowed to play g2 and h2 respectively.
And so on} 1.Se2-d4! g5-g4! 2.Sd4-e6?? {the B's are pats!
Composing this would already please a beginner composer like me. Of course, for Turnbull, it's not enough....

}
1.Se2-d4! g5-g4! 2.Sd4-f3!! g4*f3 {only one move, but from now on none of the f3, g3 and h3 pieces can play

}
3.Kf5-f6!! {So far, there is no evidence that either of the two Kings has played a move longer than 1, so they are not constrained.
The B's are now in zugzwang and will be forced to play a move that will strongly degrade their possibilities..} 3...Kh5-g4
4.Kf6-g6! { BK having now played a diagonal move, it no longer has a legal move..

}
4...h6-h5 {forced} 5.Kg6-g5# ! {note that} 5.Kg6-f5 {would be illegal because it would be checked !}

All this is perfectly explained by the Master in his report, I just wanted to go into a little more detail.
The other examples would deserve the same work to make them accessible to the greatest number, and to pay all the more homage to Turnbull's genius, but it is also necessary to leave an advantage to the face-to-face course (not to say "live").
Have a good holiday.

Add a comment