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MatPlus.Net Forum General Petko Petkov: HS# Min is also interesting!
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(1) Posted by Marjan Kovačević [Tuesday, May 2, 2017 16:41]

Petko Petkov: HS# Min is also interesting!

This highly interesting proposal by Petko Petkov deserves a separate thread, out of "12th BPCF":


The definition is analogical: Help - selfmate Min is a new condition, with the help-play before the last two half- moves, presenting S#1 Minimummer (Black has to play the geometrically shortest longest move).
1. Educational Example(P.A.Petkov): White: Ka6,Qa7(2); Black Ka2, rb8,rh4 (3) - hs#2,5Min
a6, a7, a2, b8 h4

Solution: 1...Rb2!2.Qd7 Rhb4! 3.Qa4+ Rxa4#! But not 1...Rh3? 2.Qc5 Rhb3 3.Qa3+? and now follows not 3...Rxa3# bur 3...Kxa3! Therefore the key - move 1...Rb2 blocks the square "b2" because of 3.Qa4+? Kb2!!

2. Educational Example (P.A.Petkov): White: Ka1,Ra7,Pe7(3); Black Kb5, ra8,sd1,bh7 (4) - hs#3 Min - 2 solutions
a1, a8, e7, b5, a8 d1 h7
Solutions: I.1.Ra3 Ra4 2.e8S Ka5 3.Sc7!Rxa3#; II. 1.Ra4 Ra5 2.e8Q+ Ka6 3.Qb8!Rxa4#

We can define the new hs# type as a general condition rule as follows: hs#(N)(X) Where: N is the number of moves, and X is an appropriate fairy condition, which has to be fulfilled. Of course this fairy condition can be not only Max. or Min.
Pay attention that in hs#(n)max. or hs#(n) min the fairy condition affects only one half-move - of black pieces. But in many other "additional conditions"(of type X!) the fairy condition can affect two last half-moves!
For example: we have: HS#3 Sen. - where the last part s#1 is under the Sentinels rules!!

3. Educational Example (P.A.Petkov):White:Ka1,Qg8, Rc4,Sb1 (4); Black: Kd3, Pd2(2)- hs#3 sen.-
a1, c4, g8, b1, d3, d2
solution: 1.d1S! Re4 2.Qa2 Sb2 and then follows Sentinels s#1 - 3.Qc4(w.Pa2)+!Sc4(b.Pb2)#!

Of course the "main part" of the stipulation can be also HS=, HS==, HS+ etc. An other idea is also to play in the n-1 moves under fairy condition "A" but in the last nth move under the fairy condition <. For example , possible is: Hs# Max + Minimum - this means: n-1 moves Minimum but in the last move Maximum etc.
I'm preparing a special article on this topic.But no doubt the beginning of the great idea gave MatPlus!

pid=15395 [Edit]

(35) Posted by Geoff Foster [Tuesday, May 2, 2017 11:36]

Thanks to Petko for his very interesting post. The solution of Example 3 should start 1.Re4 d1S (not 1.d1S Re4)! Unfortunately the first two examples are cooked (I didn't check Example 3).

Example 1 is cooked by 1...Rh1 2.Q~ Ra1 3.Qb3+/Qb2+ Kxb3/Kxb2#

Example 2 has several cooks, for example:
1.Ra3 Ra4 2.e8Q+ Ka5 3.Qc6 Rxa3#
1.e8Q+ Kb6 2.Q~ Kxa7 3.Qb6+/Qb7+ Kxb6/Kxb7#
1.Ra5+ Kxa5 2.e8Q ~ 3.Qb5+ Kxb5#
(Read Only)pid=15398

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MatPlus.Net Forum General Petko Petkov: HS# Min is also interesting!