# [Retros] EQUAL LAST MOVE (ELM) - 3.06.07 Updating

raosorio at fibertel.com.ar raosorio at fibertel.com.ar
Sun Jun 3 11:40:24 EDT 2007

Dear friends,

I'm posting here the ELM updated status. Wellcome to Thierry Le Gleuher and Jorge Lois.

I repeat the complete presentation in order to make the things easier for newcomers.
We are finding that the economy is based on the most clever combination of white and
black restrictions, far away in general from a straighforward extension of previous Last Move types.

I wonder if Dead Reckoning could be useful here.

You can send your originals via this RML or via private mail to me (many cases still pending)

Best,
Roberto

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EQUAL LAST MOVE (ELM)- Definition
Twinning a) white to move, b) black to move. Find the a) and b) "same nature" legal last move.

The move's nature is determined by the type of the piece/pieces involved (K, Q, R, B, N, P) and
the type of movement (simple, straight promotion, simple capture, capturing promotion, e.p.,
pawn double step, O-O, O-O-O).

An ELM problem is not (in general) a Last Move type D one. The diagram could present many legal
candidates to be the last move, but there is just one for a) and just one for b) that are of
the same nature. On the contrary, all the Last Move type DD problems are particular ELM ones.

There are 60 theorical cases (surely 57 in practice due to castlings and e.p.)
We are trying here to find the economy records (minimal pieces number). On top of records,
I think that this stipulation could be used to composse some nice problems with many tries.

Some examples are a light variation of the previous Type B ones and they are indicated as such.
Dates are reception ones.

K- (3+2=5) (8/8/8/6R1/7k/8/7K/6Rb) Bernd Schwarzkopf/9.05.2007
KxQ (2+11=13) (8/ppppppp1/7p/7R/7K/8/7k/6nn) Bernd Schwarzkopf/9.05.2007
KxR (3+3=6) (bK6/8/bk6/NP6/8/8/8/8) Bernd Schwarzkopf/9.05.2007
KxB (2+3=5) (K1k5/2rp4/2P5/8/8/8/8/8 ) Bernd Schwarzkopf, Werner Keym/9.05.2007
KxN (3+2=5) (K7/8/k7/P7/8/8/7b/6Q1) Bernd Schwarzkopf/9.05.2007
KxP (1+5=6) (8/8/8/1q1r4/k7/n1K5/5q2/8) Bernd Schwarzkopf/9.05.2007

Q- (8+3=11) (8/8/8/8/8/1P6/bPPPP1K1/Q1Bkq3) Bernd Schwarzkopf/9.05.2007
QxQ PENDING
QXR PENDING
QXB PENDING
QxN (5+2=7) () Thierry Le Gleuher /14.05.07
QXP PENDING

R- (5+4=9) (8/8/8/7p/4k2r/6KP/5PP1/6bR) Bernd Schwarzkopf/9.05.2007
RXQ PENDING
RXR PENDING
RXB PENDING
RXB PENDING
RXP PENDING

B- (7+4=11) (8/8/1p6/b7/8/P2P4/P1kPP3/K1Bb4) Bernd Schwarzkopf/9.05.2007
BXQ PENDING
BXR PENDING
BXB PENDING
BxN (4+5=9) (2b5/3p4/8/8/8/6P1/5Pr1/3k1KBr) Bernd Schwarzkopf/9.05.2007
BXP PENDING

N- (5+3=8) (8/8/8/8/8/8/kPP1P3/Nbn1K3) Bernd Schwarzkopf/9.05.2007
NxQ (3+10=13) (1nbk2NR/1p1ppppK/p6p/8/8/8/8/8) B.Schwarzkopf/9.05.2007 (Ty B,V. Bartolovic, R. Buljan)
NXR PENDING
NXB PENDING
NXN PENDING
NXP PENDING

P- (2+2=4) (8/8/8/8/8/6P1/7p/5K1k) Roberto Osorio/20.04.2007
P-- (3+3=6) (8/7p/7P/6pK/5k1P/8/8/8) Bernd Schwarzkopf/9.05.2007
PxQ (3+9=12) (8/8/8/8/4N1K1/5P1P/6Pp/4BkNb) Bernd Schwarzkopf/9.05.2007
PxR (7+2=9) (8/8/8/4KR2/7P/7P/6Pp/5BkN) Bernd Schwarzkopf/9.05.2007
PxB (6+2=8) (8/8/8/4KN2/7P/7P/6Pp/6Nk) Bernd Schwarzkopf/9.05.2007
PxN (5+2=7) (8/6K1/7P/8/8/7P/6Pp/6Nk) Bernd Schwarzkopf/9.05.2007
PxP (5+2=7) (8/4K3/8/8/7P/5N1N/6Pp/7k) Bernd Schwarzkopf, Werner Keym/9.05.2007

P-=Q (5+2=7) (7Q/8/8/7P/8/6K1/6P1/5Bkq) Bernd Schwarzkopf/9.05.2007
P-=R (5+2=7) (7R/8/8/8/8/6P1/5K1P/5Brk) Bernd Schwarzkopf/9.05.2007
P-=B (2+3=5) (7B/6p1/8/8/8/7K/8/6bk) Bernd Schwarzkopf/9.05.2007
P-=N (2+4=6) (7N/8/8/8/8/8/5pr1/3k1K1n) Bernd Schwarzkopf/9.05.2007

PxQ=Q (2+12=14) (nQr1n3/1ppKp1p1/kp1pp3/8/8/8/8/7q) Werner Keym/9.05.2007
PxQ=R (2+12=14) (nRr1n3/1ppKp1p1/kp1pp3/8/8/8/8/7r) Werner Keym/9.05.2007
PXQ=B PENDING
PXQ=N PENDING

PXR=Q PENDING
PxR=R (7+2=9) (7R/5K2/6P1/8/8/1P6/kP6/NrB5) Bernd Schwarzkopf/9.05.2007
PxR=B (2+8=10) (4rnBr/5Kp1/4r3/8/81p6/2k5/b7) Jorge Lois & Roberto Osorio/2.06.07
PXR=N PENDING

PxB=Q (2+7=9) (5KQn/4pbn1/8/8/8/1p6/2k5/q7) Jorge Lois & Roberto Osorio/2.06.07
PxB=R (5+2=7) (R7/2K5/1R6/8/8/P7/k7/rR6) Bernd Schwarzkopf/9.05.2007
PxB=B (2+7=9) (5KBn/4pbn1/8/8/8/1p6/2k5/b7) Jorge Lois & Roberto Osorio/2.06.07
PXB=N PENDING

PxN=Q (2+6=8) (KQn5/1pp5/kp6/8/8/8/8/q7) B.Schwarzkopf/9.05.2007 (Type B,many authors)
PxN=R (4+2=6) (1R6/2K5/8/8/8/P7/k7/rR6) Bernd Schwarzkopf/9.05.2007
PxN=B (2+7=9) (5bBn/6pK/4p3/7k/8/8/8/6nb) Jorge Lois & Roberto Osorio/2.06.07
PxN=N (2+5=7) (6KN/5r1r/6n1/8/8/8/2k5/1n6) Jorge Lois & Roberto Osorio/2.06.07