At first, I was going to just respond in the comments, but after a few attempts, I decided it would best be an article of its own. 

He said: 

I've always been somewhat bemused by the notion that God lost in the Garden of Eden, that Satan won, and that there was this mad scramble in Heaven to come up with a "Plan B".

Ask yourself this, "If Adam and Eve weren't supposed to fall, why didn't God just start over again with a new couple in the Garden of Eden? Had he lost the power to create such a couple?"

When you realize that the Fall was planned from the beginning, it all makes sense.

This presents the idea that God had written this drama from the beginning, which would logically lead to the idea that our fates were already decided beforehand. This is a topic that inevitably gets brought up when discussing God at length, which usually triggers a debate between free will and determinism. I can assume the commenter takes the side of determinism, at least in some capacity. 

Personally, I take the side of free will. 

In order to take that side, I have to square how an all-knowing would allow for such a thing to happen. As the commenter suggests, if He is all-knowing, and knew we would fall, why wouldn't he just start again? My response to that is because he is not just "all-knowing," He is also a "loving" God with a love so deep that it's hard to comprehend it in its totality. How does this answer the question? 

Stick with me.

A very interesting thing popped up on my YouTube algorithm after I read that question the following day, as if God was answering the question Himself. It was a video from a man named Nicholas Bowling talking to an atheist woman on the street who said that most people will be going to Hell, and as such, she can't follow that kind of God. 

"Why would God create this dichotomy in the first place? Why would He give humans free will, fully knowing — because He's all knowing — that this would happen to most humans? It doesn't make sense.

Bowling gave a fantastic answer, asking the woman if she could imagine a man who kidnapped her and imprisoned her in his basement, and told her that she would be his wife, she will love him, and she would have and raise his children. He asked her if that would be love. The atheist woman answered that it wasn't, to which Bowling agreed, pointing out that he had taken the woman's free will away from her. Then he made his point. 

"God doesn't do that," said Bowling. "He's not going to take you, and force you to love Him like that kidnapper. So He gave free will so that there can be love." 

Bowling added that if someone came up to the woman and wooed her, and she fell in love with him of her own accord, going on to marry him, she did so out of her own free will, and that's the love God wants. 

To get back to my commenter, the reason God let us fall even though He knew we were going to is because he is a God who knows that love and free will are intermingled, and you cannot have one without the other. 

So loving is our God that you can actually see His emphasis on free will in various Biblical passages, starting with Genesis 2-3 when Adam and Eve ate the apple, naturally, but there are others. 

God also emphasizes choice to Cain before he kills Able in Gensis 4:6-7 when God said to Cain, "If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must rule over it.”

In Deuteronomy 30:19 God is directing Israel to make a choice with Moses as his spokesman saying, “This day I call the heavens and the earth as witnesses against you that I have set before you life and death, blessings and curses. Now choose life, so that you and your children may live." Here is God offering the choice to do as one pleases, but points out which way is the right way, which is a habit of God's throughout humanity's existence. 

Joshua 24:15 also emphasizes a choice to either follow or reject God with Joshua saying to Israel: “But if serving the Lord seems undesirable to you, then choose for yourselves this day whom you will serve, whether the gods your ancestors served beyond the Euphrates, or the gods of the Amorites, in whose land you are living. But as for me and my household, we will serve the Lord.”

I could go on, but you get the point. Free will was always at play from the very start, and we chose imperfection. 

Now, does this mean God "lost?" Not at all. It's necessary, at this point, to understand what God is, and while I'm not daring to say I understand His mind, I can at least recognize an inth of His capabilities based on what I've learned about Him. 

God isn't just some mystical being who can see the past, present, and future. He's much more than that. He is a multidimensional, cosmic mathematician whose calculations are so accurate that He can measure the results of every action, choice, and event down to how the movement of a blade of grass will affect outcomes 1000 years down the line. He's that precise. Hard to fathom, I know, but such is His power and understanding. 

This means that God knew we, as the imperfect beings we are, would trip and fall, which means He didn't have a "Plan B," as the commenter suggested. He was already proactive in how He would fix this problem, and as you study the Bible, you'll see this system of events He put in place to bring us back, culminating in the crucifixion. There was never a need for a "Plan B," there is just "the plan." 

Let's look at it this way. When you have a child, and they're learning to walk, you know they will stumble and fall down. The solve for this is to guide them and keep your hands nearby or supporting them as they learn to take steps and keep their balance. Do you toss the child out because they didn't learn to walk immediately and were perfect in their balance? No, because that would be stupid. You love them too much and besides, you understand their stumbles. 

Now take that and make it into a cosmic undertaking. 

God did not plan the fall, but He did plan for the inevitability of it happening, and He let it happen because if He stopped it and forced us to do as He wanted, then He wouldn't have creatures who loved Him and obeyed Him of their own accord. He'd have automatons, and these aren't capable of love. He wants His children to choose to be with Him forever. 

And to choose requires free will, and God is all about free will.