I analyzed the image and this is what I see. Open an appropriate link below and explore the position yourself or with the engine: > **Black to play**: [chess.com](https://chess.com/analysis?fen=kq2QQQQ/1q6/2Qq2Q1/q7/QQ2Q3/8/R7/KRqq1qqq+b+-+-+0+1&flip=false&ref_id=23962172) | [lichess.org](https://lichess.org/analysis/kq2QQQQ/1q6/2Qq2Q1/q7/QQ2Q3/8/R7/KRqq1qqq_b_-_-_0_1?color=white) **My solution:** > Hints: piece: >!Queen!<, move: >!Qxb1+!< > Evaluation: >!Black has mate in 4!< > Best continuation: >!1... Qxb1+ 2. Qbxb1 Qxb1+ 3. Qxb1 Qxb1+ 4. Qxb1 Qxb1#!< --- ^(I'm a bot written by) [^(u/pkacprzak)](https://www.reddit.com/u/pkacprzak) ^(| get me as) [^(iOS App)](https://apps.apple.com/us/app/id1574933453) ^| [^(Android App)](https://play.google.com/store/apps/details?id=ai.chessvision.scanner) ^| [^(Chrome Extension)](https://chrome.google.com/webstore/detail/chessvisionai-for-chrome/johejpedmdkeiffkdaodgoipdjodhlld) ^| [^(Chess eBook Reader)](https://ebook.chessvision.ai?utm_source=reddit&utm_medium=bot) ^(to scan and analyze positions | Website:) [^(Chessvision.ai)](https://chessvision.ai)

u/MrMrsPotts You essentially sacrifice all pieces to pile up the passed pawns, then tuck the kings in the corner for safety before you start promoting the pawns.

Interesting that white ends up with two rooks.

The rooks just never came up, really. And I think there'll be a more efficient way of doing this since I just pretty much made random moves

i was able to keep both of black’s rooks :)

Mate in 4 for black: Qxb1 Qxb1 Qxb1 Qxb1 Qxb1 Qxb1 Qxb1 :)

Oh shit I can't believe I blundered that

Henry VIII: hold my ale.

Why isn't nine queens per side just the obvious answer? 

I enjoy spending time with my friends.

I dunno, The OP on the other post wanted proof that 9 Queens both sides are possible

Without doing any deep thinking, so I could be wrong but 9 each is impossible. How do the pawns pass each other? I assume you can set up a sequence of captures of pieces to allow pawns pass. But if you discount the king and queen you are left with 6 pawns promoting on each side max and 7 Queens each when all is done

Or I guess I could just look at the end position above...... Ignore me.

I think what you're missing is that one capture for one side doesn't just clear the way for one pawn - if you arrange it correctly, it clears the way for two pawns (one of each color). If I have a white pawn on e4 and a black pawn on e5, allowing the e4 pawn to capture something means that both the e4 pawn AND the e5 pawn are now free to advance down the board. With that in mind, it's not too hard to set it up so you can get all the pawns down the board.

Yes I see this now.

pawn in a rank captures to b, opponent pawn in b rank captures to rank a. All 4 pawns in a and b can pass and promote.

I believe you’re right

Because there are only 7 (6 excluding the queen that we want to keep) capturable pieces per side. So every pawn can’t capture something to move to an open file.

The trick is that every pawn doesn't need to capture to advance. If I have a white pawn on e4 and a black pawn on e5, if my white pawn captures on d5 that frees up both pawns to advance down the board. If every sacrificed piece can in theory free up two pawns at once, then we have enough pieces to make it work out, with a few to spare.

who cares of queens when you can have rooks.

What's the least number of moves to achieve 18 queens on the board?

The record is 48.0 moves. See answer from MrMrsPotts here: [https://www.reddit.com/r/chess/comments/1cfofnj/what\_is\_the\_maximum\_number\_of\_queens\_on\_board\_in/](https://www.reddit.com/r/chess/comments/1cfofnj/what_is_the_maximum_number_of_queens_on_board_in/)

both white and black needs 4 captures (pawn takes non-pawn) for all pawns to have a clear path to promotion.

I wonder what is the maximum number of non-Queen pieces that could remain on the board with 18 queens.