[Retros] EQUAL LAST MOVE (ELM) 17.06.07 updating

[raosorio at fibertel.com.ar]

Dear friends, 

I'm posting here the ELM updated status. 

I repeat the complete presentation in order to make the things easier for newcomers. 

News include the ELM RxR and PxR=Q cases, which are still pending in the Last Move Type DD
record table.

You may 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, i) means improved from previous updating, and n) means new. 

I included the reference of the Last Move Type DD record (Type DD is the particular Type D cases 
where the last move is of the same nature both for WTM and BTM) in the form of DDxx, where xx 
is the number of pieces in the corresponding DD record. 

For instance, in the following first case the move is K-, after that DD12 indicates that the DD 
record uses 12 pieces, and after that (3+2=5) means that the ElM record uses 3 white pieces 
and 2 black pieces, total 5. Then, the FEN, author and reception date. 

K- DD12 (3+2=5) (8/8/8/6R1/7k/8/7K/6Rb) Bernd Schwarzkopf/9.05.2007 
i)KxQ DD24 (1+11=12)(3nK2k/ppppp2p/4p2n/7p/8/8/8/8) Bernd Schwarzkopf/14.06.2007 
KxR DD22 (3+3=6) (bK6/8/bk6/NP6/8/8/8/8) Bernd Schwarzkopf/9.05.2007 
KxB DD14 (2+3=5) (K1k5/2rp4/2P5/8/8/8/8/8 ) Bernd Schwarzkopf, Werner Keym/9.05.2007 
KxN DD10 (3+2=5) (K7/8/k7/P7/8/8/7b/6Q1) Bernd Schwarzkopf/9.05.2007 
KxP DD24 (1+5=6) (8/8/8/1q1r4/k7/n1K5/5q2/8) Bernd Schwarzkopf/9.05.2007 

i)Q-DD13 (5+4=9) (8/8/8/3k4/8/PP6/qnpP4/1QK5) Bernd Schwarzkopf/08.06.2007
QxQ DD?? PENDING 
QXR DD?? PENDING 
QXB DD?? PENDING 
QxN DD12 (5+2=7) (8/8/8/8/8/P7/1PP5/qQK1k3) Thierry Le Gleuher /14.05.07 
QXP DD26 PENDING 

R-  DD13 (5+3=8) (8/8/8/8/1p6/P7/rPP1k3/1RK5) Bernd Schwarzkopf/08.06.2007 
RXQ DD17 PENDING 
n)RXR DD??(7+4=11)(3Q1B1r/5kpP/5NR1/5KpB/8/8/8/8) Roberto Osorio & Jorge Lois/16.06.07 
RXB DD18 (4+4=8) (8/8/8/8/1p6/p7/rPP1k3/1RK5) Bernd Schwarzkopf/08.06.2007 
RXN DD9 (3+4=7) (8/8/8/8/8/np6/rP2k3/1RK5) Bernd Schwarzkopf/08.06.2007 
RXP DD25 PENDING 

B-  DD12 (7+4=11) (8/8/1p6/b7/8/P2P4/P1kPP3/K1Bb4) Bernd Schwarzkopf/9.05.2007 
BXQ DD24 PENDING 
BXR DD11 PENDING 
BXB DD27 PENDING 
BxN DD11 (6+2=8) (8/8/8/8/8/4P1PP/5BPb/4K2k) Bernd Schwarzkopf/06.06.2007 
BXP DD26 PENDING 

N-  DD11 (5+2=7) (8/8/8/8/8/5K2/4PPPk/6Nn) Bernd Schwarzkopf/08.06.2007 
NxQ DD17 (3+10=13) (1nbk2NR/1p1ppppK/p6p/8/8/8/8/8) B.Schwarzkopf/9.05.2007 (B,Bartolovic, Buljan) 
NXR DD16 PENDING 
NXB DD19 ( 2+7=9) (5KNr/4p1np/4q3/5k1b/8/8/8/8) Roberto Osorio & Jorge Lois/9.06.07 
i)NXN DD17 (5+3=8) (8/8/8/8/7P/4K1kP/6Pn/6Nb) Bernd Schwarzkopf/12.06.2007
NXP DD25 PENDING 

P-  DD8 (2+2=4) (8/8/8/8/8/6P1/7p/5K1k) Roberto Osorio/20.04.2007 
P-- DD17 ( 3+3=6) (8/7p/7P/6pK/5k1P/8/8/8) Bernd Schwarzkopf/9.05.2007 
PxQ DD24 (3+7=10) (8/8/8/8/4N1K1/5P1P/6Pp/4BkNb) Bernd Schwarzkopf/9.05.2007 
PxR DD21 (7+2=9) (8/8/8/4KR2/7P/7P/6Pp/5BkN) Bernd Schwarzkopf/9.05.2007 
PxB DD16 (6+2=8) (8/8/8/4KN2/7P/7P/6Pp/6Nk) Bernd Schwarzkopf/9.05.2007 
PxN DD16 (5+2=7) (8/6K1/7P/8/8/7P/6Pp/6Nk) Bernd Schwarzkopf/9.05.2007 
PxP DD18 (5+2=7) (8/4K3/8/8/7P/5N1N/6Pp/7k) Bernd Schwarzkopf, Werner Keym/9.05.2007 

P-=Q DD20 (5+2=7) (7Q/8/8/7P/8/6K1/6P1/5Bkq) Bernd Schwarzkopf/9.05.2007 
P-=R DD20 (5+2=7) (7R/8/8/8/8/6P1/5K1P/5Brk) Bernd Schwarzkopf/9.05.2007 
P-=B DD10 (2+3=5) (7B/6p1/8/8/8/7K/8/6bk) Bernd Schwarzkopf/9.05.2007 
P-=N DD16 (2+4=6) (7N/8/8/8/8/8/5pr1/3k1K1n) Bernd Schwarzkopf/9.05.2007 

PxQ=Q DD24 (2+12=14) (nQr1n3/1ppKp1p1/kp1pp3/8/8/8/8/7q) Werner Keym/9.05.2007 
i)PxQ=R DD23 (2+12=14) (5+6=11) (6R1/4Kpp1/5ppN/8/8/8/1R6/krN5)Bernd Schwarzkopf/12.06.2007
PXQ=B DD25 PENDING 
PXQ=N DD24 PENDING 

n)PXR=Q DD?? (3+6=9) (4rnQ1/5Kp1/8/8/8/5P1k/4r3/6q1)Jorge Lois & Roberto Osorio/14.06.07 
PxR=R DD20 (7+2=9) (7R/5K2/6P1/8/8/1P6/kP6/NrB5) Bernd Schwarzkopf/9.05.2007 
PxR=B DD24 (2+8=10) (4rnBr/5Kp1/4r3/8/81p6/2k5/b7) Jorge Lois & Roberto Osorio/2.06.07 
PXR=N DD24 PENDING 

i)PxB=Q DD26 (2+6=8) (5nQK/5pr1/8/8/8/1p6/2k5/q7) Jorge Lois & Roberto Osorio/14.06.07 
PxB=R DD16 (5+2=7) (R7/2K5/1R6/8/8/P7/k7/rR6) Bernd Schwarzkopf/9.05.2007 
PxB=B DD25 (2+7=9) (5KBn/4pbn1/8/8/8/1p6/2k5/b7) Jorge Lois & Roberto Osorio/2.06.07 
n)PXB=N DD16 (4+3=7) (7N/5K1k/6R1/6Q1/8/8/8/6bn) Roberto Osorio & Jorge Lois/16.06.07 

i)PxN=Q DD23 (5+2=7) (5nQK/5pr1/8/8/8/8/2k5/1q6) Roberto Osorio & Jorge Lois/16.06.07
PxN=R DD14 (4+2=6) (1R6/2K5/8/8/8/P7/k7/rR6) Bernd Schwarzkopf/9.05.2007 
PxN=B DD24 (2+7=9) (5bBn/6pK/4p3/7k/8/8/8/6nb) Jorge Lois & Roberto Osorio/2.06.07 
PxN=N DD22 (2+5=7) (6KN/5r1r/6n1/8/8/8/2k5/1n6) Jorge Lois & Roberto Osorio/2.06.07