My thoughts on SC2John's excellent post (look in the spoiler), so that MOBA players can see that it is relevant to them too. I will use an SC2 example at the bottom to help those who play both games:
+ Show Spoiler +
http://www.teamliquid.net/forum/viewmessage.php?topic_id=435534
The art of the imaginary player, and knowing WHEN and HOW you plan to win:
This is where due to unknown information you have to make wide decisions that incorporate all potentials.
The first thing this requires is a large amount of understanding and experience of the game itself.
Then how does this apply? Think about team drafting.
The important skill for the player(s) picking is to be able to work out any potential builds (strategies/game plans) the other team is trying to do as they pick their hero. To give an example from dota (and i'd appreciate a good lol player giving a lol example, as i'm sure it applies):
After the 3rd pick, the other team has chosen venge, luna and dazzle.
There are lots of possibilities from here.
One of those possibilities might be that they plan on running an aura team. However, due to the dazzle pick this might not be that obvious. There is still a lot of information that is unavailable.
They might just like venge and luna, and are going to go ahead and try to play what i like to call pub-standard, 2-1-2, where people pick heroes that work well as a combo for laning and don't think about the wider plan.
What is important here in the context of the imaginary player is not to think about what they are ACTUALLY thinking. Only what they COULD be thinking, no matter how likely. Sure, near the bottom of the ladder they might just be picking heroes/champions based on what they feel like doing, but that doesn't matter, because at BEST they will do a shitty version of what you are thinking about. React based on their best possible decision, while leaving yourself open to a wider set of choices.
The key here is to RULE OUT STRATEGIES. In this example, we KNOW they aren't doing a mass aoe team fight winning team. So you don't need to pick warlock to fuck up a potential enigma pick. Sure, they MIGHT pick enigma, but in this team enigma would be BAD, so don't prepare for it, a normal, well rounded team will crush this hard regardless. A good idea might be to pick a caster heavy team and try to dominate the early mid game will high burst spells vs his low hp, low burst team. The key here would be to win in the mid game.
This is why the logic that less good starcraft players use when they say: "Ah, but scouting in gold league doesn't matter because they might just be doing stupid things" is bad logic.
To give another concrete example: I scout a Terran who has taken double gas before expanding and put 3 in each geyser. I immediately rule out a bio push with early stim but no medivacs. I have had players say to me, but he MIGHT still push and just not use his gas. Yes that is true. And if he does it will be 3 minutes late and with almost no units. In the mean time, your preparation for a 1-1-1 or helbat/mine drop was much more effective, and the units you built to deal with that are enough to hold off his much delayed push.
I hope this hasn't been too all over the place and it has been helpful in clarifying thoughts you probably have already had but not been able to put into words.