# How many moves needed to reach this position?

"Homebase" is where all the surviving pieces are apparently on their starting squares. Here is a very easy new example proof game: can you find the unique shortest game that leads to this position?

``````[Title "A.Buchanan 26-11-2020 Facebook: shortest proof game?"]
[FEN "rnbqkbnr/ppppppp1/8/8/8/8/PPPP1P1P/RN2K1NR w - - 0 1"]
``````

Yes c1 is empty!

I have no idea about this kind of problems, but my guess would be something like this.

``````[FEN ""]

1. g4 h5 2. Bg2 hxg4 3. Bf3 gxf3 4. Kf1 fxe2+ 5. Kg2 exd1=R 6. Kf3 Rxc1 7. Ke2 Re1+ 8. Kxe1
``````

Is that unique? I have no idea.

• @RewanDemontay thanks for the edit, how does that work? Simply adding [FEN ""] before the moves? And then presumably enter the position in the quotation marks if it's not the starting position. Commented Nov 25, 2020 at 18:59
• Very nice - and yes it’s unique. Can you make sure this is concealed by spoiler protection, so others can have a go Commented Nov 25, 2020 at 19:10
• @Laska do you happen to know if there is a way to hide a diagram? So apparently spoilers can be used through the usage of >! ? But then the diagram is gone again. Commented Nov 25, 2020 at 19:16
• @koedem I don't know how to hide a diagram: maybe ask in meta Commented Nov 26, 2020 at 8:54
• Spoilers are very limited in what formatting they support; the replayer won't work in them. I feel that people who visit the page know there must be solutions below, so a spoiler isn't really necessary. Commented Nov 26, 2020 at 9:29

For a partial answer, here are a semi-unique sequence sin 11 moves. They are no doubt revealing of the true solution's strategy.

``````[FEN ""]

1. e4 h5 2. Qxh5 Rxh5 3. g4 Re5 4. Bc4 Rxe4+ 5. Kf1 Re1+ 6. Kg2 Rxc1 7. g5 Re1 8. Be6 Rxe6 9. g6 Rxg6+ 10. Kf1 Rh6 11. Ke1 Rh8
``````

Or this.

``````[FEN ""]

1. e3 h5 2. Qxh5 Rxh5 3. g3 Rh3 4. Bd3 Rxg3 5. Kf1 Rxe3 6. Kg2 Re1 7. Bf5 Rxc1  8. Bg4 Re1 9. Bh3 Re3 10. Kf1 Rxh3 11. Ke1 Rh8
``````

And this.

``````[FEN ""]

1. e4 h5 2. Qxh5 Rxh5 3. g3 Re5 4. Bh3 Rxe4+ 5. Kf1 Re1+ 6. Kg2 Rxc1 7. Kf3 Re1  8. Kg2 Re3 9. Kf1 Rxg3 10. Ke2 Rxh3 11. Ke1 Rh8
``````
• Good experiments! But the actual solution is a lot shorter! Commented Nov 25, 2020 at 17:43