[Retros] Retros Digest, Vol 146, Issue 5

[Dominique Forlot]

You 're absolutly rignt !

Oh damned ! I apologise twice here : https://www.youtube.com/watch?v=jLz9qzvjAB0

thank for all these precisions !

friendly :o)

Dominique.






> Message du 02/09/16 15:33
> De : retros-request at janko.at
> A : retros at janko.at
> Copie à : 
> Objet : Retros Digest, Vol 146, Issue 5
> 
>Dominique Forlot wrote:
> 1.Cg1-f3 Cb8-c6 2.Cf3-e5 Cc6-d4 3.Ce5xd7 Cd4xe2 4.Cd7xf8 Ce2-f4 5.Dd1-h5 Fc8-g4 6.Ff1-c4 Fg4-d1 7.Dh5xf7
> > mat(0,17,7) 
> D(13ply) = 39,69410640 
> vitesse 3.053393/ply (and not 2.5117/ply !! :o( ).
>

> But the PG you gave is a mate(0,16,8), so it's even better:
> distance = 40.515961
> speed = 3.116612/ply .
> 
> 
> Dominique Forlot wrote:
>"Compose the shortest sound checkmate PG witch beat the slowest speed record" > the mat(4,4,0) 9.656854 lenght for 9 plies for example have a speed of :1,0729837...and the lower limit of the speed is ... 1

> There is no mate(4,4,0) in 9 plies, my mate(4,4,0) was in 6 plies.
> 
> Among all sound checkmate PGs in 6.0 moves or less, the slowest average speed is 1.112967 obtained from (8,3,0) in 11 plies:
> 
> 1. e3 f6 2. e4 Kf7 3. e5 Kg6 4. e6 Kg5 5. d3+ Kh4 6. g3#
> 1. f3 b6 2. f4 Bb7 3. f5 Qc8 4. f6 Kd8 5. fxg7 f6 6. gxf8=Q#
> 1. f3 b6 2. f4 Bb7 3. f5 Qc8 4. f6 Kd8 5. fxg7 f6 6. gxf8=R#
> 1. h3 b6 2. h4 Bb7 3. h5 Qc8 4. h6 Kd8 5. hxg7 h6 6. gxf8=Q#
> 1. h3 b6 2. h4 Bb7 3. h5 Qc8 4. h6 Kd8 5. hxg7 h6 6. gxf8=R#
> 
> The fastest average speed is 4.740194, coming from (38,10,0) in 11 plies which I've already discussed.
> 
> 
> Dominique Forlot wrote:
>To specify my thought on the problem of the matt by "knight alone" :
> > because of mat(∅,∅,c) : « Knights alones» is unsound [...]
>
> Compose a sound checkmate PG wicth "maximize" the geometric score = c*sqr(5) - (α + β*sqr(2))

> In 6.0 moves or less, the best score I get is 26.832816 for (0,0,12):
> 
> 1. Nf3 Nf6 2. Ne5 Ne4 3. Nxd7 Nxd2 4. Nxb8 Nxf1 5. Nd2 Ne3 6. Nf1 Nxg2#
> ... 4. Nxf8 ...
> ... 4. Nb6 ...
> ... 4. Nc5 ...
> ... 4. Ne5 ...
> 
> What was your proof that mate(0,0,c) is unsound? :o)
> 
> 
> roberto osorio wrote:
>Three geometrical types of moves: orthogonal, (2,1), diagonal, i.e., N, SQR5, SQR2. Due to the opening, the task of 100% moves of just one type for a checkmate is only feasible for (N,0,0).
>I found a sound one in 14 single moves. Is there some one shorter? Surely this is easy to asnwer for Francois.
> Wow, another non-believer in the power of knights! :o)
> 
> For (N,0,0), the shortest is in 5.5 moves, with N going from 21 to 29 in 5.5 moves, and from 25 to 41 in 6.0 moves:
> 
> (21,0,0) in 5.5 moves: 1. d4 a5 2. d5 Ra6 3. d6 Rxd6 4. Qxd6 f6 5. Qxf6 h6 6. Qg6#
> (29,0,0) in 5.5 moves: 1. d4 h5 2. d5 Rh6 3. d6 Rxd6 4. Qxd6 a6 5. Qxa6 f5 6. Qg6#
> (25,0,0) in 6.0 moves: 1. a4 a5 2. Ra3 Ra6 3. Rc3 Rd6 4. Rxc7 Rxd2 5. Rxd7 Qxd7 6. b3 Rxd1#
> (41,0,0) in 6.0 moves: 1. h4 h5 2. Rh3 Rh6 3. Rd3 Ra6 4. Rxd7 Rxa2 5. Rd3 Qxd3 6. f4 Qg3#
> 
> François
> 
>
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