Chess puzzle

I encountered some puzzles recently that i couldnt figure out, even after seeing the solution i did not understand them. Maybe someone can explain the solution to me?

https://www.chess.com/puzzles/problem/32187

https://www.chess.com/puzzles/problem/1000568

The first puzzle:

Notice that black's king could be vulnerable to back rank mate, due to the shield of pawns. Also, white's rook on e1 is pointing directly at that back rank. So, White plays

2. Qf3!

Black, apparently not being a very smart opponent, captures the queen.

2... Bxf3??

3. Rxe8#

As for the second puzzle, I'm not sure. The analysis seems to randomly say White is positionally winning by 5 points.

Hope this helps.

Edit - Actually, I was looking at the analysis for the second puzzle a little bit more, and apparently

2. Kxf2??

Leads to make in 12. That seems like a very difficult puzzle, to have to spot a mate in 12!

I dont quite understand how we can just assume black to make a mistake in a puzzle. That seems really odd to me since you should always assume your oppnent plays the best move in puzzle, or am i mistaken?

Thanks for taking your time to write an explanation though, i appreciate it.

oh nice, i just checked it out, really fun

Yes. That is usually true. But, if we only learn to play against opponents who make good moves, we'll never be able to take advantage of your opponents' bad moves! Once, in a game I was playing, my opponent hung his knight. I was thinking about my move for about 30 seconds, when I realized, "Oh wait. I can literally just take a free knight"!

So it's good to have a balance in puzzles.

No, you can't assume anything about your opponents' play. The point is to find a solution that works no matter what the opponent plays.

In the first puzzle, Qf3 works because black can't defend the e4 bishop. The bishop can't take the queen (because of mate), can't move away (because of mate), and black can't defend it with f5 (because the pawn is pinned). So black loses a piece.

Att12's explanation was not good. He only covered half of half of the solution.

The second puzzle is more difficult, yes.

If white accepts the sacrifice: 2. Kxf2 Qe3+ 3. Ke1 (no other move) Rf8!

Rf1 mate is threatened, and white can only delay it by throwing away the queen. There is absolutely no need to calculate mate in 11 or whatever. The explanation of Att12 is again not good.

If white rejects the sacrifice, the e2 bishop is hanging and is pinned. White's kingside is in ruins. An example line: 2. Re1 (defending the bishop) Qe3 and good luck surviving this.

Ahh I see, thank you for the thorough explanation magipi. Really bothered me not being able to figure out those puzzles, but now i finally understand the solution.

@magipi

You're so rude! You don't have to say that my answer was not as good as yours! The point of the forums is so that multiple people can answer someone's question! You being critical of what I said has absolutely nothing to do with what you are saying!

I wasn't rude. I didn't say anything bad about you, I just said that your answer was not good. Which it wasn't.

@magpi

That's not even what I said. I said you were being critical of my answer. I didn't say that you were personally insulting me.

Well, your answer was bad, wasn't it? For both puzzles.

I did not want to hurt your feelings, so sorry about that. Let's move on.

Yes

@magpi

You're not responding to what I am saying! Every time I say that you are being unnecessarily critical of my answer, you just say that my answer was bad, which has nothing to do with that!