Infinite chess openings

Good question. Btw in addition to openings, a summary of minimum material to mate would also be interesting. For example, can RRK mate against K?

I am pretty sure that any number of knights cannot mate against a king. A king can walk as fast as two knights, and will just keep walking away from them. If a third knight participates, they can't walk as fast as the king.😕

I'm pretty sure RRK can force mate against a lone king. It will be more tricky than RK vs K on a normal board, but the theory will be similar. The one rook will act as the edge of the board, while the other rook and king will force the king towards that edge. I can't see how the king can avoid this net.

As for knights... I doubt three knights can force mate, but then again I can't see anyone ever promoting to knight, seeing as a chancellor will do the same and more. But yeah you're probably right in that the king should be able to keep running, since only one knight can move faster than the king, and that knight will not be able to stop it fleeing further from the other knights.

Yeah for sure we can force mate, but we'll need to use boths rooks, we can't  have one simply being an "edge".

Looking at that position, it's actually mate in three, but I was trying to demonstrate the method.

1. Re8... already the king is contained

1... Kd6 2. Ra7

1... Kd4 2. Ra3

1... Kd6 is ILLEGAL!

Nope.

-_- I put in Ra6 then Re8.

I saw it too!

BDF defense?

DONE!

You welcome.

Cardinaivary?

Scandinavian?

Sounds pretty cool.