
Best moves for white to win this crucial game
There was a reason the OP didn't show coordinates. 1.b8Q is one of at least a dozen winning moves for White. And "crucial" was not really the right word for this game.
This is a win for both black and white since there is no way of telling which way the pawns push. E1 could be the central dark square at the bottom or the top. But I think by looking at the pawn structure, we might be able to tell if it is possible for the white pawns to push down. My guess is that black is winning.
The position is legal with either White or Black at the bottom. I don't agree that "there is no way of telling". We're asked to find White's win, suggesting Black is at the bottom. But we're also told the game is crucial, suggesting White is at the bottom. (The game could only be crucial if it's a genuine game from a real event.)
So I guess we can take our pick. But to go along with the joke, we have to assume Black is at the bottom.
What??? Black has the blue pieces and it's White's move. How is Black going to win against 1.b8Q?
We don't know if blue represents black.We don't know if a1 is at the top or at the bottom.I wonder then if we can draw safe conclusions regarding "White's plan for the win" ?!
I suppose we could ask the OP to tell us if Black has the blue pieces. If so, then the task of finding a win for White tells us whether a1 is at the top or bottom.
To me it seems more natural that White is at the top,so blue is white and Kb2 is a good plan for the win.
To me, it's obvious that the OP intended for Black to be playing the blue pieces, from the bottom.
You may well be right,in reality I have no idea and my hypothesis is purely intuitive.