[Retros] shortest proofgames of castling switchback

[Mario Richter]

Dear Noam,

unfortunately both problems are cooked:



> hg-19.0

> NDE 15.vii.2007

> rQB1k2r/p1pppp1p/np3npR/1b2b3/P6P/1P1PR1Pq/2P1PP1B/1N2K1N1


In the first some moves can be interchanged
(in your solution 12.Re3, in the cook 12.Bh2):

 1.a2-a4 g7-g6 2.Ra1-a3 Bf8-g7 3.Ra3-h3 Bg7-e5 4.d2-d3 Ng8-f6 5.Qd1-d2 O-O
 6.Qd2-h6 Kg8-h8 7.Bc1-f4 Rf8-g8 8.Qh6-f8 b7-b6 9.Rh3-h6 Bc8-a6
 10.h2-h4 Qd8-c8 11.Rh1-h3 Qc8-b7 12.Bf4-h2 Ba6-b5 13.Rh3-e3 Nb8-a6
 14.g2-g3 Qb7-g2 15.Qf8-b8 Qg2-h3 16.Bf1-g2 Kh8-g7 17.Bg2-b7 Rg8-h8
 18.Bb7-c8 Kg7-f8 19.b2-b3 Kf8-e8


The second


> hg-21.5

> NDE 16.vii.2007

> 1n4n1/1pp1p3/3p1ppb/p4rrp/3Q2k1/1PN2BPb/P1PPPP1P/RqB1K1NR


can be done without 0-0:

1.b2-b3 a7-a5 2.Bc1-a3 Ra8-a6 3.Nb1-c3 Ra6-g6 
4.g2-g3 Rg6-g5 5.Bf1-g2 h7-h5  6.Ke1-f1 Rh8-h6 
7.Bg2-d5 d7-d6 8.Kf1-g2 Qd8-d7 9.Kg2-f3 Qd7-h3
10.Qd1-c1 Qh3-f1 11.Qc1-b2 Qf1-b1 12.Kf3-g2 Rh6-f6 
13.Nc3-d1 g7-g6 14.Kg2-f1 Bc8-h3 15.Kf1-e1 Ke8-d7 
16.Bd5-e4 Kd7-e6 17.Be4-f3 Ke6-f5 18.Bf3-e4 Kf5-g4 
19.Qb2-d4 Rf6-f5 20.Ba3-c1 f7-f6 21.Nd1-c3 Bf8-h6
22.Be4-f3 

Regards,

  mario