﻿﻿ MatPlus.Net

Website founded by
Milan Velimirović
in 2006

4:59 UTC
 ISC 2024

Remember me

 CHESS SOLVINGTournamentsRating lists1-Apr-2024
 B P C F

MatPlus.Net Forum General Name for this type of Hamburg

### Name for this type of Hamburg

Wilhelm Massmann
Miniatures stratégiques, 1935
P1167277
(= 4+3 )

#3
Try: 1 Rf5+? Ka6!
Solution: 1 Rf6 (thr 2 Rb6+ Ka4/Ka5 3 Qa7#) Ra5/Ra6/Ra8 2 Rf5+ Ka6 3 Ra5#; 2 ... Ka5 3 Qf4#

White has a mainplan Rf5+. Ka6 refutes 1 Rf5+. After White has played the foreplan (unless Black played Ra6) Black can play exactly the same move Ka6. However, this fails for one reason or another: 1 ... Ra5 walks into a skewer and 3 Rxa5#; 1 ... Ra8 is a critical move across a6 as a result of which 3 Ra5 is mate.

This is White decoy of Black's rook. However, the consequence of it being decoyed is not that Black can't play Ka6 any longer (they can), but rather that it no longer prevents #3. Is there a name for this phenomenon, where, after White plays the foreplan and the mainplan's first move, Black can play exactly the same move as refuted the try?

(If I understand the concepts right, if Black's try-refuting piece and decoyed piece are the same piece, then this wouldn't qualify as Roman, because the reason why the refutation-move fails after the foreplan must be something different from decoy.)

(2) Posted by Thomas Maeder [Tuesday, Jan 16, 2024 20:49]

In a Roman, the black defender is decoyed in the foreplan, so that his successful defense is replaced by a different, unsuccessful one. In a Hamburger, almost the same thing happens, but it's not the defender which is decoyed, but a different black piece.

In the Massmann problem, Black has the same defense in the try and and the real play after the foreplan. This is therefore neither a Roman nor a Hamburger.

The idea of making a successful defense unsuccessful is so common and simple that I don't think there is a name.

1. - Ra8 is a critical decoy over a6, causing 2. - Ka6 to become an interception.

1. - Ra5 is another decoy, but not a critical one; here, Black's damage is the loss of control of a5.

1. - Ra6 is a Beugung (deflection): among >1 defenses, Black loses its successful one because of a decoy.