Body: <p>I am trying to track a very special proof game I saw many years ago when I learned about proof games (a board position is given, and the challenge is to find the unique sequence of moves from the initial set-up that reaches the given position in the stipulated number of moves).
  The only info I remember is that the final position had only rooks (perhaps 10 per player?), and that the number of moves was ridiculous; something like 35.
  That same afternoon I downloaded the program Natch to verify the problem, so I might have found it in a page that linked to the Natch page, although I am not sure of that.</p>
  <p>Any leads?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-16T04:45:47.153Z
Comments.Text: Probably Pronkin & Frolkin 1987 or a closely related proof game in 55+ moves where each side has a King, comically many Rooks, and a few other men.  See for example the accepted answer to Chess Stack Exchange #29362 <https://chess.stackexchange.com/questions/29362>.
Comments.UserDisplayName: Noam D. Elkies
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-16T08:41:40.837Z
Comments.Text: If the final position had 10 rooks / player then there must be at least 40 moves just to promote them all. I think it's unlikely that the PG is unique, but older problems do allow play to be non-unique
Comments.UserDisplayName: Laska
Tags: <problems><retrograde-analysis><identify-this>
Title: Long proof game with rooks
ThreadText: # Long proof game with rooks
  
  (Asked by: username_0 on 2024-07-16)
  
  I am trying to track a very special proof game I saw many years ago when I learned about proof games (a board position is given, and the challenge is to find the unique sequence of moves from the initial set-up that reaches the given position in the stipulated number of moves).
  The only info I remember is that the final position had only rooks (perhaps 10 per player?), and that the number of moves was ridiculous; something like 35.
  That same afternoon I downloaded the program Natch to verify the problem, so I might have found it in a page that linked to the Natch page, although I am not sure of that.
  
  Any leads?
  
  **Tags:** problems, retrograde-analysis, identify-this
  
  > **Comments:**
  > **username_1**: Probably Pronkin & Frolkin 1987 or a closely related proof game in 55+ moves where each side has a King, comically many Rooks, and a few other men.  See for example the accepted answer to Chess Stack Exchange #29362 <https://chess.stackexchange.com/questions/29362>.  
  > **username_2**: If the final position had 10 rooks / player then there must be at least 40 moves just to promote them all. I think it's unlikely that the PG is unique, but older problems do allow play to be non-unique  
  
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  ## 0 answers
  
  