[Retros] Question on SPG conventions

[Andrew Buchanan]

Colleagues,

A question I've had for a while... 

Suppose in a sound SPG, a composer might equally well choose to place a 
certain pawn on the 3rd or the 4th rank. In the latter case, a smidgeon of 
extra logic is required to deduce that the pawn must have made a double-hop, 
so this one is essentially identical to the former case. 

Is there any stylistic convention which would guide the composer in this 
tiny choice? 

Similarly, suppose a line piece might validly be placed on any of several 
squares along the final line of movement, and there is no thematic reason to 
prefer any one square. 

Does any stylistic convention help in choosing the square? 

Thanks,
Andrew Buchanan.