I like this kind of puzzle.. You don't have to calculate the next move, instead you should answer the question below and prove your point.

It's Black to move, according to regular chess rules, can Black castle?



The only tip available is: There has been no capture in the past 2 moves.

Will post the answer hidden tomorrow. Enjoy!

PS: I don't have the source, I was presented this puzzle last week, will try to get the source name from a friend of mine.

No. White couldn't get his rook to f1 or move anything else to reach that position, therefore this position could not theoretically occur with no captures in the past two moves.

But you nearly tricked me, I spent 2 minutes trying to prove the opposite and failing

Another note: This forum requires that you wait 30 seconds between posts. Please try again in 1 seconds.

Haha good catch on the post delay message

Now, you are close but what if White castled last move?

Evidence 1

Evidence 2


Conclusion


cheers

But I think the hint: "No captures in two previous moves" refers to two plies. So after taken back O-O, white's previous move could possibly be e2xXf3.
However, further conclusion:

I thought of your solution too. I guess both are acceptable and have similar conclusions.