THE LOGIC AND BEAUTY OF THREAT CORRECTION
by Valery Shanshin, in collaboration with Marjan Kovačević and David Shire
Part IV
There are numerous aesthetic tools and patterns in chess composition. One such device is that of the same move repeated in a different context, so creating an aesthetic impression and stressing the priorities in the content. These priorities have a most important role in the logical combinations of #2, based upon the precise elaboration of play. (The terms 'logical' and 'logical combination' in this article should not be interpreted in the way whose terms are used by the Logical (New German) School of composition, but rather in a natural way  Ed.)
In the previous parts we have seen some examples of TC using this principle of "unrepetitious repetition" (e.g. No 8 and No 15 with the Caprice theme and No 37 with its choice of means to activate a royal battery). And naturally this phenomenon is the essence of TTC.
The effect of repetition is intensified by the additional means of changed play and changing movefunctions (e.g. white moves recurring as key/try, threat and mate; black moves recurring asd defence and refutation  DS). This direction has been investigated over many years. Consider No 40 where different thematic elements create a very harmonious threephase complex!



№ 40. 1.Bc6? – 2.Sf3#, 1...Qxh2 2.Bd4#, 1...f3 2.Lg3#, 1...Qxf2!; 1.Bd5!? – 2.Qe6(А)# (2.Sf3?), 1...Sc7 2.Sf3#, 1...Kxd5 2.Qf5(В)#, 1...Sbd4 2.cxd4#, 1...f3!
1.Be4! – 2.Qf5(В)# (2.Sf3?), 1...Sg3 2.Sf3#, 1...Kxe4 2.Qe6(А)#, 1...Sed4 2.cxd4#
In the recent No 41, the interchange of primary and secondary threats unites both systems of TC.
№ 41. 1.Sd~? – 2.Qd4(A)#, 1...Sc2 2.Qf3#, 1...Rc7!; 1.Sxf5!? – 2.Qg4(B)# (2.Qd4?), 1...gxf5 2.Qd4#, 1...Kxf5 2.Sd6#, 1...gxh5!;
1.Sd8(g5)? – 2.Qg4(B)#, 1...gxh5 2.Rxf5#, 1...e4!
1.Sxe5! – 2.Qd4(A)# (2.Qg4?), 1...Rxe5 2.Qg4#, 1...Kxe5 2.Sc4#, 1...Sc2 2.Sd3#
To me astonishment I discovered that the French duo went even further long ago. No 42 presents the complete interchange of the same two thematic finales in both the threats and variations. In this way further unity is assured!
№ 42. 1.Se~? – 2.Rf3(A)#, 1...Se5 2.Sf5(B)#, 1...Be1 2.Rxd3#, 1...Rxb2!; 1.Sc3!? – 2.Sf5(B)# (2.Rf3?), 1...Sxd6 2.Rf3(A)#, 1...Qc8!; 1.Be~? – 2.Sf5(B)#,
1...dxe2 2.Rf3(A)#, 1...Sxd6!
1.Bxd3! – 2.Rf3(A)# (2.Sf5?), 1...Be1 2.Sf5(B)#, 1...Se5 2.Qe4#, 1...Kxd3 2.Qxb3#
At the time No 43 was composed, the author had not a clue regarding the concept of TC. His aim was to realize an extended antidual choice of threat, beginning from the random move of the keypiece and being doubled through the play of both wSs.



No 43. The setplay 1...cxd3 2.Qh5# and 1...cxd4 2.Qa8# shows the direction of the attack – the d4 square.
The Barnes try 1.Rxc4? – 2.Qh5, Qa8# is refuted by 1...axb3!
1.S3~? – 2.Qh5# (2.Qa8?), 1...cxd4!;
1.Se5(A)!? – 2.Sdc6(B)# (2.Qa8?, Qh5?), 1...Kxe5 2.Qh5#, 1...cxd4 2.Rb5#, 1...Bxc4!
The other wS is the correct one: 1.S4~? – 2.Qa8# (2.Qh5?), 1...cxd3!
1.Sc6(B)! – 2.Sde5(A)# (2.Qh5?, Qa8?), 1...Kxc6 2.Qa8#, 1...cxd3 2.Bxe4#
The interchange of first moves and threats of the two main phases serves as an inherent link between both lines of play.
The next composition (No 44) came on the wave of inspiration that the joint work on these articles brought to me! It adds significant depth to the parallel conceptual lines.
No 44. An introductory phase activates the setplay: 1.Sd2? – 2.Se4#, 1...Sd6 2.Ke7#, 1...Bxf3 2.Kg6#, 1...Sg5 2.Kxg5#, 1...Re1!
The removal of wSе6 activates the royal battery: 1.Se~? – 2.Ke6#, 1...Sf4(g5) 2.Kg5#, 1...Bxf7 2.Kxf7#, 1...Rg1!; 1.Sg5!? – 2.Ke6#, 1...Sf4! (2.Kg5?);
1.Sd4!? – 2.Qa1# (2.Ke6?), 1...Kxd4 2.Ke6#, 1...Rxf1!
Hope remains in the removal of wBf5: 1.Bf~(e4)? – 2.Kf5#, 1...Bg4(g6) 2.Kg6#, 1...Rg1!;
1.Bg6!? – 2.Kf5(A)#, 1...d2 2.Qc2(B)#, 1...Bg4! (2.Kg6?); 1.Bg4!? – 2.Kf5#, 1...d2!
The key is to move wBf5 with Caprice effect! 1.Bxd3! – 2.Qc2(B)# (2.Kf5?), 1...cxd3 2.Kf5(A)#, 1...Kxd3 2.Qd2#
In No 45 all three phases present the same two thematic finales.
No 45. 1.Bd~? – 2.d4(A)#, 1...d5 2.Sd3(В)#, 1...e5!; 1.Bc4!? – 2.Sd3(B)# (2.d4?), 1...B:c4 2.d4(A)#, 1...Sb4!
1.Bb5! – 2.Qxc6# (2.d4?), 1...Sb4 2.d4(A)#, 1...cxb5 2.Sd3(B)#
The further perspectives in developing the content are easy to foresee: the complete form of TTC (No 46) on the one hand and the complete cyclic change of three white moves (No 47) on the other.



No 46. 1.Sc~? – 2.Bc6(A)#, 1...Sf3 2.Qd3(B)#, 1...Bb7!; 1.Se5!? – 2.Qd3(B)# (2.Bc6?), 1...R:e5 2.Bc6(A)#, 1...Rd6!
1.Sd4! – 2.Qf5# (2.Bc6?, Qd3?), 1...Qxf1 2.Bc6(A)#, 1...Qc(d)5 2.Qd3(B)#
No 47. The set flight 1...Kc4 lacks provision so 1.S~? – 2.Qd3(A)#, 1...e4 2.Qc3(B)#, 1...c4 2.Qe3(C)#, 1...Bb1!; 1.Sxe5!? – 2.Qe3(C)# (2.Qd3?), 1...Bxe5 2.Qd3(A)#, 1...Re4 2.Qc3(B)#
(1...K:e5 2.B:g7#), 1...Bh6!
1.Sxc5! – 2.Qc3(B)# (2.Qd3?), 1...bxc5 2.Qd3(A)#, 1...Rc4 2.Qe3(C)# (1...Kxc5 2.Qxd5#)
Amazingly, this most complex aggregation presented above had already been achieved long ago (No 48), although with first moves executed by different white pieces:
No 48. In the set position Qb1# doesn't work because of the d4 flight, while for Sg5# to succeed we need an extra control of e5.
1.Sf5? controls d4 and allows the planned threat 2.Qb1(A)#, with 1...d4 2.Sg5(B)# and 1...Kxf5 2.Qxd5(С)#, but 1...f3!
1.Rf3!? controls both d4 and e5 but the f3 flight determines the threat 2.Sg5(B)# with 1...Sxf3 2.Qb1(A)# and 1...Kxf3 2.Qxd5(C)#, but 1...Sh3!
The keysacrifice1.Rd3! includes two weaknesses, cardinally changing the situation: the closure of the b1e4 diagonal prevents 1.Qb1# while
the d3 flight excludes 2.Qg5#. However, the control of the d5 square turns a previous variation mate into the threat 2.Q:d5(C)#! The thematic play
is completed by the variations 1...K:d3 2.Qb1(A)#, 1...cxd3 2.Sg5(B)#. The byplay consists of two changed mates: 1...d4 2.Qf5#, 1...f3 2.Rd4# (set 2.Rg4#)
Multiple and successive TC effects may form a closed circuit. In such a case, the synthesis of logical combinations and the change of movefunctions may produce an indivisible whole. No 49 proves the point in a light construction, again with first moves by different white pieces.



No 49. 1.Sg2? – 2.Qf4(A)# (2.Qe3?), 1...e5 2.Qe3(B)#, 1...Rf1!; 1.Sc4? – 2.Qe3(B)# (2.Qe5?), 1...Rd3 2.Qe5(C)#, 1...Re1!
1.Rc6! – 2.Qe5(C)# (2.Qf4?), 1...R:d5 2.Qf4(A)#
(In the UK we would probably regard this as a cyclic form of the Suchkov theme  DS)
No 50 may help to reveal the hidden possibilities of enriching the cyclic form of TC with paradoxical effects. (Readers may wish to revisit No 33 from the 3rd Part in order to compare the perspective of its creator with that of the composer of No 50 currently under review.)
No 50. 1.Sg5? – 2.Qxe4(A), Qxc6(B)#, 1...Sc5 2.Sxb6(C)#, 1...Rxc4 2.Re5#, 1...Sd6!; 1.Sd4!? – 2.Qxc6(B), Sxb6(C)# (2.Qxe4?), 1...R:c4 2.Qxe4(A)#, 1...Rc3!
1.Sc5! – 2.Sxb6(C), Qxe4(A)# (2.Qxc6?), 1...Rxc4 2.Qxc6(В)# (1...Kxc4 2.Ba2#)
The Le Gramd theme may also be an organic part of TTC as achieved in No 51.
No 51. 1.Sf8? – 2.Sxe7(A)#, 1...Sxd3(x) 2.R3e4(B)#, 1...Se4!; 1.Se5!? – 2.R3e4(B)# (2.Sxe7?), 1...Sxd3(x) 2.Sxe7(A)#, 1...Rh4!
1.Sxc5! – 2.Sb3# (2.Sxe7?, R3e4?), 1...bxc5 2.Sxe7#, 1...Sxd3 2.R3e4# (1...Kxc5 2.Qxb6#)
It is regrettable that one of the main variations repeats in the solution.
In recent times we have witnessed a breakthrough of correction play into heterodox genres and it is good to see logical concepts spreading throughout chess composition. This does not mean the time has come to give up on the search for new combinations in the logical #2. To give an idea about the possible future of TC. we will conclude this series of articles with two convincing examples!


No 52. 1.Be3? – 2.Qd4#, 1...Bxe3 2.Qxe3#, 1...Rf4!; 1.e3? – 2.Qd4#, 1...Rf4 2.exf4#, 1...Rxd2!; 1.Sf~? – 2.Sf3#, 1...Bb6!; 1.Sd4? – 2.Sgf3#, 1...Be3!
1.Se3! – 2.Sg4# (2.Qd4?, Sf3?), 1...Kf4 2.Qd4#, 1...Rf4 2.Sf3#, 1...Sf2 2.Sxh3#
A logical, consecutive choice of 3 arrivals on the same square plus an analogous choice of 3key moves by the same white piece plus related threat corrections. So here we find an extraordinary synthesis of arrival correction, white correction and threat correction!
No 53. 1.S7~?  2.Qh7#, 1...Be7!; 1.Sg6!? – 2.Sg5# (2.Qh7?), 1...Be5!; 1.Sf5!? – 2.d3# (2.Qh7?), 1...Bb4!
1.Sxd5! – 2.Sc3# (2.Qh7?, Sg5?, d3?), 1...cxd5 2.Qh7# (2.Sg5?, d3?), 1...Bb4 2.Sg5# (2.d3?), 1...Be5 2.d3# (2.Sg5?), 1...Kxd5 2.Bf3#
Thus it is seen that the key phase is tertiary both with respect to 1.Sg6!? and 1.Sf5!?
These two systems of TTC and the Hannelius pattern with antidual choice of mates in the solution are organic parts of the whole concept.
(The defensive work of the bBd6 confers an outstanding degree of unity  DS)
Valery Shanshin (Russia), in collaboration with Marjan Kovačević (Serbia) and David Shire (Great Britain)
January 19, 2016