[Retros] 9 white pawns, cont'd

[Noam Elkies]

I wrote:
 

>>> George Leathem

>>> The Problemist FCS 821 05/1933

>>> 8/3pPKPp/4N1N1/4PkP1/3P1p1P/3PRPRP/8/5Q2

>>> #1



>> On further thought, even after removing one of White's nine pawns

>> the position is illegal WTM unless it's the e5 or g5 pawn that's removed

>> (when Black could have just played 0...e5xf4 or g5xf4); perhaps that's

>> what Mario R. was hinting at. 



> Exactly!



>> Removing Pe7 also results in an impossible pawn configuration



> As well as the removal of Pe5,Pd4 or Pd3. [...]



>> There's also a dual mate Qb1(d3) in the -Pd3 branch.  It seems that

>> this is easily fixed by moving Re3,g3 to e1,g1, which also lets us

>> eliminate the retro-illegality issue by moving wPf3 and bPf4 down to

>> f2 and f3 -- again assuming that we can retract 0 e2xd3++ (or 0 g2xh3++)

>> Kf5 without introducing too many pawn captures on any of the seven

>> branches that keep Pd3 and Ph3 on the board.



> Positions after -Pe7, -Pe5 -Pd4 (and also after -Pd3) are still illegal ...


And if we also shift everything one square left?  That should eliminate
at least a few captures.

NDE