possible or impossible?

2nd:

I was looking at DavidMertz1's analyses and I was thinking how do I leave the Bishop on the board?

EDIT: further analyses:

You guys found a possible last sequence, great. But a legal game leading to that position with the light square bishop must be proven possible, of course.

Well, since you insist.  We have proven your supposedly impossible to be possible.  Now you need to explain why you thought it was impossible :)

Good job - also, I mixed up the positions by mistake, it is the other way around - first position is impossible and the second position is possible, oops 

Now, all that's left is to explain why the first position is impossible. Anyone up for it?

...

Yeah sorry about that, I just shouldn't give hints, I always mix things up 

here's another one, it's not so hard, but I wanted to make one that's drawn and my engine says it's won for black. If you think it's win for black you can post your analyses as well, really, it isn't that hard.

This is obviously drawn.  White moves Kg2 - Kh1 in perpetuity.  Black can take all of White's black colored pawns, but that won't help.  Black's king cannot penetrate until a light colored pawn is gone, but that will never happen.  Also, there is no way to trap White's king and thus force White to take one of Black's bishops, opening a path.

And keeping in the spirit of the thread, the position is possible.  White captures 2 black knights and 2 black rooks with his pawns, Black underpromtes the A,C,E,and G pawns to bishops, all other pieces are thrown away however you like.

You're right DavidMertz1! This is possible because of the Bishops being the promoted pawns.

the first one is impossible because of the centre pawns:

hmm... does white have enough pieces for that? I was thinking it's kinda the same...

Here's another one:

and another one

and this one

and last

273 is impossible since White has all his material but Black has 2 c-pawns.  The others look possible to me.

Well that isn't really true...

White doesn't have all of his pieces

White has a knight for his h pawn. The h pawn couldn't have promoted with the other pawns in that position if there was a capture on the c file.

you're right... I forgot that there are 3 knights... you're both right. i'm sorry.