The Holst promotion theme

The Holst promotion is an appealing idea that exemplifies the school of logical problems. The latter refers to a type of three- and more-mover in which White’s strategy consists of two stages – called the foreplan and the mainplan – that must be executed in the right order. The mainplan begins with a try-move that can be thwarted by Black, and in the case of the Holst theme, this refutation is delivered by a black pawn promoting to a certain piece. Accordingly, White first carries out a foreplan designed to force the pawn to promote to another kind of piece, after which the mainplan can proceed without hindrance. The theme is named after Viktor Holst, a Danish composer who pioneered the idea in the 19th century.

The first diagram brings about a tripling of the Holst theme in a miniature setting. If White advances the king to control b5 (Black’s only flight-square), that will threaten a bishop mate on c8. The three possible king approaches represent separate mainplans that – if played immediately – are defeated by different queen promotions: 1.Kc4? c1=Q+!, 1.Kb4? e1=Q+!, and 1.Ka4? a1=Q+! White therefore starts with a foreplan aimed at inducing these pawns to promote to something else. 1.Bf5! creates a mating threat, 2.Bd3, that’s stoppable only by various knight promotions. Since each defence of this type deprives the pawn of the option to become a queen, White can safely respond with the appropriate king move or mainplan. 1…c1=S+ 2.Kc4 ~ 3.Bc8, 1…e1=S 2.Kb4 ~ 3.Bc8 (2…Sd3+ 3.Bxd3), and 1…a1=S+ 2.Ka4 ~ 3.Bc8/Bd3.

Before we consider two complex demonstrations of the theme, readers are referred to two other clear examples found elsewhere on this site. (1) Weekly Problem No.589, a four-mover by Günther Flad, and (2) Problem No.88 in Problem World, Promotion Play – Part 1, a four-mover by Erwin Guttmann. The second one illustrates a consecutive Holst, in which Black makes two thematic promotions in a single variation.

A particularly deep rendition of the theme is seen in the above more-mover, a famous piece of work. White aims to mate by firing the B + K battery on the long diagonal, but Black’s considerable force seems capable of restraining the king. The mainplan 1.Kd5? threatens 2.Kxc4, and while 1…Qb4? is inadequate against 2.Kc6 (for 3.Kc7), Black refutes with 1…c1=Q! 2.Kc6 B~ when the new queen neutralises the white bishop, or 2.Sxc1 allows 2…Qxb2 3.Kxc4+ Qg2. White thus concocts a foreplan to provoke a knight promotion, and starts by pushing the king in the opposite direction. 1.Kf3! (for 2.Kg4) Rh4 (not 1…Rg5? 2.fxg5) 2.Kg2 (for 3.Kf1) dxe2 (not 2…Rxf4? 3.Kh3+). Now that White’s e2-knight has been annihilated, the switchback 3.Kf3 carries the threat of 4.Kxe2, which is preventable only by 3…c1=S. Then 4.Ke4 (for 5.Kf5) Rh5 brings the king back to its initial position, at which point the original mainplan becomes effective. 5.Kd5 (for 6.Kxc4) Qb4 6.Kc6 (for 7.Kc7) Qe7 7.Kb5+ Qb7 8.Bxb7. This composition, featuring a remarkable king journey, attained the rare maximum 12 points in the FIDE Album of its period.

The four-mover elaborates on the theme in an intriguing way. The b7-bishop has two plausible options to threaten mate, 1.Bd5 (2.Bxc4) and 1.Bf3 (2.Be2). Neither move works as the key, however, due to two different promotion defences by the c2-pawn (the g6-bishop is stuck defending another bishop mate on e4). 1.Bd5? c1=Q! 2.Bf3 Sc3 and despite the self-block on c3, 3.Sb2+ fails because of the new queen. 1.Bf3? c1=S! 2.Bd5 Sb3+ – the new knight manages to give a disruptive check. The key 1.Bh6! attacks e3, meaning the d1-knight cannot move without permitting a rook mate on that square. Now 2.Bd5 works as a thematic threat, acting as a foreplan that compels 2…c1=Q, followed by the mainplan 3.Bf3 Sc3 4.Rxe3 (or 3…Bh5 4.Be4), since 3…c1=S is precluded. So the threat-play yields a standard Holst, although uncommonly the knight promotion is the strong defence that White seeks to eliminate.

The subtle 1…b3 prepares for a queen check – 2.Bd5? c1=Q 3.Bf3 Qa3+, but in obstructing b3, the pawn also hinders a potential black knight check. As a result, White is able to switch the two bishop moves and reverse their functions: 2.Bf3 becomes the foreplan that forces 2…c1=S, then 3.Bd5 serves as the mainplan (not disturbed by 3…Sb3+) – 3…Sb2 4.Rxe3 (or 3…Bf7 4.Be4), exploiting the unavailability of 3…c1=Q. Such a logical problem scheme, in which two different promotions by a single black pawn alternate as the strong and weak defences, is called a reciprocal Holst. Here it is accomplished in a masterfully constructed setting with no white pawns. There is also full-length by-play: 1…c1=S 2.Sb2+ Kc3 (2…Sxb2 3.Rxe3) 3.Sxd1+ Kd3 4.Rxe3 and 1…e2 2.Sc6 (3.Sxb4) a5 3.Re3+ Sxe3 4.Se5.

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16 Aug. 2022