Pendulum

A repeated movement of a piece between two squares a and b. No less than three moves are required.

Hegermann, Bernard

The Problemist FCS, 1934

Example: Pendulum
h#28  (11+7)

1.Kxh8 Kh1 2.Kg8 Kg1 3.Kf8 Kh1 4.Ke8 Kg1 5.Kd8 Kh1 6.Kc7 Kg1 7.Kd6 Kh1 8.Kxe6 Kg1 9.Kf6 Kh1 10.Kg5 Kg1 11.Kf4 Kh1 12.Kxe4 Kg1 13.Kd4 Kh1 14.Kc3 Kg1 15.Kxb3 Kh1 16.Kxb4 Kg1 17.Kxb5 Kh1 18.Kc4 Kg1 19.b5 Kh1 20.b4 Kg1 21.b3 Kh1 22.b2 Kg1 23.b1=Q Kh1 24.Qf5 Kg1 25.Qf7 gxf7 26.Kc3 f8=Q 27.Kd2 Qc8 28.Ke1 Qc1#

Pendulum record: 24 moves of wK.

View in Helpmate Analyzer

FEN: 6kR/4p1p1/1p2P1P1/1P2p3/1P2P3/1P2p1p1/4P1P1/5BK1

External links:

Krampis, Illo

Die Schwalbe, 2019

Example: Pendulum
h#4  (9+10)

1.Qxh1 Ra8 2.Qxa8 a7 3.Qh1 a8=Q 4.Qe1 Qf3#

BQ pendulum corner-to-corner.

View in Helpmate Analyzer

FEN: q7/R1Kp1p2/Pp1Pp1p1/b3P1Pp/8/2p5/4Pk1B/7N

External links:

Semenenko, Valerij

Die Schwalbe, 2018

Example: Pendulum
h#6.5  (2+11)

1...Bxh8 2.Ke7 Ba1 3.Qb2+ Kd3 4.Qh8 Ke4 5.Qe8 Bh8 6.Bh6 Ke5 7.Bf8 Bf6#

WB pendulum corner-to-corner.

View in Helpmate Analyzer

FEN: 4k2n/3p1p2/1n6/2p5/pp6/q3bp2/2K5/B7

External links:

Abdurahmanović, Fadil

Die Schwalbe, 2010

1st Prize

Example: Pendulum
h#6  (2+12)

1.Be6 Kd1 2.Qe5 Ke2 3.Kf5+ Kf3 4.Bb3 Bc4 5.f6 Bg8 6.Be6 Bh7#

BB pendulum.

View in Helpmate Analyzer

FEN: 8/3p1p2/8/n5pp/4k3/pbp5/p6q/2K2B1r

External links: