Shortest-proof-game challenge

3563

Here's one needing to be shortened.

aah yes that is known as the queen opening, very common among low rated players

44.5 moves, don’t see how to do it shorter.

Pitty I have not seen this thread before now…

Well done for finding the bishop zigzag! That is the crux of the problem, seeing how it must have made 13 moves minimum.

Here’s a slightly shorter proof game, optimising the route of the black rook starting on h8:

Edit: black rook now on a2.

Loved that Bishop manoeuvre, but it took some time to figure out exactly when to open and close lines with the Pawns. Nice puzzle 👍. So I’m expected to post the next one? Will look at it tomorrow then, bedtime now.

edit: Nope, beaten. Nice…

You must add an extra move to get the Rook to a2, but still better than mine. Nice detail playing the Rook along the third rank. And nice trip for the White Queen 😊.

The rules from #1 were old and now anyone is free to post a position, regardless if they found the fastest solution to the previous position or not. You don’t have to post the next position, but you could if you wanted to…

I thought this was a hard one. I was glad just to find a proof game, without worrying about how long it was. I was about to post my 53.5 move game when lubaza's post appeared.

Just before I log off: I have looked through some pages in this thread, but gave up when I realised the size of it. So I ask instead without knowing if it has been brought up: before:

Do you know what is the longest known shortest proof game? Does not have to be a unique shortest for that position, just one of the shortest possible.

Unless it's changed recently, the longest known unique SPG is 57.5 moves. I could post it here if you like. I'm not sure about the longest non-unique SPG.

In Die Schwalbe I just found an entry for a 185-move non-unique SPG.

Thanks for your reply. That is really impressive! By searching, I found this one from 2018, probably the same source?

The reason why I asked was because I knew about another retro puzzle that needed a lot of moves to release the position and tried to find a SPG for it (with some minor adjustments). Far less than 185, bit still big though. Will post the challenge here, and I'm pretty sure I have found a SPG.

Pretty sure this is the fastest (well, so I claimed in the previous problem, and I was wrong, but still...), as I see no fewer moves for any of the pieces.

Seems to be a unique SPG as well.

Here is the position for an SPG (not unique) of 185 moves, in case anyone wants to try finding it.