Illegal Position Contest!

P.S. That was my lame idea of a joke, since #7799 is illegal. White needs six pawn captures, and the capture at c8 makes seven, but Black is only missing six units.

Every time I try to make the position look more legal, I end up actually making it legal... I had originally been intending to post the version with the knight, but I thought it would look more spacious with a bishop instead, which made the position legal by allowing an alternate path for the black king.

Even after seeing the alternate path, I thought the position was still illegal because black wouldn't have enough captures to promote every pawn; not my intended idea, but I thought it saved me from posting something legal. Unfortunately for me, it turns out that black doesn't actually need to promote the a and b pawns.

try 7773

It's illegal even when the pawns on a4 and b6 are on a3 and b3. The number of tempi does not matter. It is possible to release 70% of the position but then there is still an "illegal island" in the upper right which can never be resolved

g7-g5 gxf7

Don't work because the black queen on f7 cannot retract to g6 due to illegal retraction check!

before ke4 and e6

When you retract (play backward) you will see that you cannot retract any king since that causes illegal checks on the other king. Retracting moves is about 10 times more efficient than playing and thinking forward moves.

No explanation of #7795 has been provided, so I will assume it was too easy. How about this position?

I think no one bothered to explain it after Ariskstotle stated at #7801 that it's perfectly illegal, although he called it #7955, a comment number still in the future. Presumably Arisktotle could be persuaded to explain his statement, if asked nicely.

I think it's rather easy to know that it's legal. White only needs two pawn captures to promote on five dark squares.

3922 in spg

Nimzowitsch Defense: Scandinavian, Bogoljubov, Vehre Variation

So we are talking #7795. I'd already given away the plot by mentioning e.p. It's one of those where you retract the king into a doublecheck which is lifted by retracting an e.p. move. Only this time it fails since you have to retract the giant pawn leap next - e7-e5 - which loses you [Bf8] in the overall material count. Only 13 black units can then be captured by white pawns while 14 are required!

Btw, the other roads Home are simply blocked by impossible retractions - much simpler than in the original version (which was flawed). Do you need more than that?

Here's a proof game for trananh6377's position. Someone else can shorten it.

See, I knew it was too easy. Hopefully my new position is a little harder.

Black's dark squares on the 8th rank are all blocked by an unmoved black pawn. The white a-c-e pawns can promote to a dark-squared bishop with one capture each, but then all White's captures will be used up and there can be no more promotions by White on dark squares. So White can have no more than four dark-squared bishops, and in this position White has six, making the position illegal.

the maximum possible dark squared bishops is ten then???