Chess Online

hint: try to study old rules of the chess

it needs old info and creativity

Nothing is impossible in the chess if u have enough info and creative thinking

In this way, you could check nine times at once (4 horses, and 5 queens eyeing the square of promotion, for instance.).

Even if there were some old rule allowing promotion to a king, it wouldn't make any difference. Promoting to a king neither leads to mate nor to a double or triple check.

Oh I see what you mean - but I am sure there has never been a law which allows you to promote to a piece of the opposite colour!

I didn't know that a pawn can be promoted to a king, more dubiously an opponent king, according to the old chess rules a few centuries ago.. One of the earliest modern chess games ever recorded dates around the 17th century.. It was a game of Gioachino Greco vs NN in 1619.. Maybe before that time a pawn was allowed to be promoted to a king.. I don't know where yelaman got his source from but that's an interesting insight.. Maybe we just don't know more about chess and its origins.. But still.......

Really? Have you got the position please?

Now that IS a triple check and mate!

fictionally ridiculous, but lovely on another sense. Notice that Euwe had to promote to a black king - he couldn't mate both kings simultaneous immediately otherwise!

very interesting even if it did begin with an illegal move by someone that really didn't know how to play the game correctly. Point is they are not old moves of Chess as stated just illegal moves)

Fail to see the connection with the puzzle?
To achieve the mate in two it's a very simple d8 = Q or R and Qc7++

Maybe I was but my other point was that he triple check example was not possible in the old rules of Chess, but a game on a train between a Master and what looks like a novice. In this case Max Euwe chose to allow what was then ant still is now an illegal move and then played one himself.

Good story, eh? lol   Max Euwe's train? I wonder if that actually happened...

.... as it seems so unlikely.

triple check can be done if three white pieces are eyeing at a square and the black king moves into that square. 

but I couldn't think of another way.