Mat Plus
Vol II, No.15, Autumn 1997

Mat Plus Challenge No.1

The article Cyclic Mating Permutations from Mat Plus 13-14/1997 has shown that the most common way to present the theme is a three-phase circular provoking of three black weaknesses: one by white and the remaining two by black in each phase. Thematic mates are motivated by these weaknesses.

Here are two examples with this method (not thematic for the tourney the announcement of which follows).

1. L. Loshinsky &
V. Chepizhny

1.pr Olymp. ty. 1960







#2vv 14+8
1.Qg4? ~ 2.d7#,
  1... Rh7,Re8,Sf7 2.Qd4,b4,Rc4#, 1... Bd5!
1.Qb7? ~ 2.d7#,
  1... Rh7,Re8,Sf7 2.b4,Qb6,Sb3#, 1... Re4!
1.Qe6! ~ 2.d7#,
  1... Rh7,Re8,Sf7 2.Rc4,Sb3,Qd5#
2. V. F. Rudenko
(after L. Zagoruiko and H. Hermanson)
cmIl Due Mosse 1959







#2*v 8+7
Set play: 1... Re4,Be3,Re5 2.Qd2,Qb4:,Qe5#
Try: 1.Sd5? ~ 2.Bc5#,
  1... Re4,Be3,Re5 2.Qa1,Qe3:,Qb4:#, 1... b3!
Key: 1.Bd5! ~ 2.Bc5#,
  1... Re4,Be3,Re5 2.Qe4:,Qa1,Qd2#
In problem by Loshinsky & Chepizhny three black line-movers guard in pairs mating squares b3, b4 and c4. In first moves white Queen closes one of them, while remaining two lines are one at time closed or abandoned by black defences. Interestingly, when closed black line is abandoned white Queen gives new mate thus producing three sets of changed mates or theme Zagoruyko 3x3! Similarly, in Rudenko's problem three squares in the black King's field (e3, e4 and e5) are guarded by white (in initial position, after the try-move and after the key-move). Remaining two are self blocked by black defences allowing the white Queen to leave the e-file and choose the mating move which preserves the guard of non-protected square. Again, when black man plays to guarded square white Queen captures it and mates, so this is also theme Zagoruyko 3x3.

"Our" theme

Let's now try something completely opposite: to do it by provocing the white weaknesses. I got the idea to try this method long time ago, but, for some reason, I never came back to it. Maybe I was subconciously trying to save it for the age when ability to invent is decreased, but compensated by greater ability to construct. Nevertheless, I have many other things "saved" for the old days so I deceided to share this one with you.

Obviously, "white weaknesses" is the other expression for mate separation or dual avoidance. However, the essence is that one of thematic mates is already prevented by white self-injury (i.e. self-interference, self-obstruction, self-pin) before black defences take place. Two remaining mates are alternatively separated by two of three thematic black defences. Scheme A shows it in an extremely primitive form. The problem with such method is how to handle the third defence in order to avoid the duals. The most probable way is to make them non-defences in respective phases, as it is shown in more conventional but still not satisfactory example B, where one white self-obstruction (on c5) is already present in the set play. This method does not seem to be suitable for the complete Zagoruyko 3x3, but I wouldn't dare to claim it impossible.

[A] Milan Velimirovic
scheme







#2 12+5
1.Bd2? (~), 1... Bd4:,Bd6: 2.Sg3,Sf2#
  1... Kd5!, (dual after 1... Bb4:)
1.Bf2? (~), 1... Bb4:,Bd6: 2.Sg3,Sd2#,
  1... Kd5!, (dual after 1... Bd4:)
1.Bg3! (~), 1... Bb4:,Bd4: 2.Sf2,Sd2#,
  (dual after 1... Bd6:)
[B] Milan Velimirovic
scheme







#2 8+9
Set play:1... Qh6,Qb3 2.Qb4,Sd6#
Try: 1.Bd6? ~ 2.Qa6:#,
  1... Qb3,d3 2.Qc5,Qb4#, 1... Kd3!
Key: 1.Bb4! ~ 2.Qa6:#,
  1... Qh6,d3 2.Qc5,Sd6#