To understand outflanking, you need to know what the opposition means.
Opposition combined with outflanking, helps you to win endgames. The outflanking maneuver helps you to penetrate the opponents position.
I'll first give you an example. If you study this, all will become clear.
I'll then show you how to use this outflanking during practical play.
As an example, you have to win this position with White.
You have the move.
And to make it a little difficult for you, you're allowed to move your rook only once.
How do you solve this problem?
Use the concept of opposition, together with the idea of outflanking.
You have to start by making your king the stronger one. You'll achieve this by taking the opposition.
You've taken the distant opposition.
You've held on to the opposition, but you couldn't move forward yet.
And now we've arrived at a key moment.
You can keep the opposition with 3.Ka2, but this doesn't help you to make progress.
You don't want to move your king to a3 or b3, because this allows Black to take the opposition and your king will be the weaker one.
There's another very good option though. You have to play:
Now you're outflanking the black king.
You're making forward progress while placing a file between the kings. You are preventing Black from taking direct opposition.
Black has to decide now how to defend. He has three possibilities: Kb8, Kb7 and Ka7.
This allows you to move forward, taking the opposition again.
And now the process will be repeated. 4....Ka8; 5.Kc5,
Outflanking once more.
You've taken the direct opposition, and Black is in trouble now. He has only one move left.
Now it's time for the final outflanking move.
You've probably found this one yourself already...
7.Kc7, and Black has only one move left:
And now, finally, the time has come for your rook to move. All the outflanking has lead to a position where the rook can deliver mate.
This move prevents you from moving forward (for the moment).
If you were to move to b4 or c4, Black will take the opposition (b6 or c6) and you cannot make any further progress.
So you have to take the opposition yourself, to make your king the stronger one again. I hope you know which move to play?
You've taken the opposition and you're ready to start a new outflanking maneuver.
4...Ka7; 5.Kc4!, moving one step forward.
One step at the time will get you to the other side.
The rest will then happen just like in the previous variation.
But... Black can try a different defence, like 5....Kb6.
This allows you to take the opposition again (I'll repeat it once more: it makes your king the stronger one).
And now Black has to retreat to the seventh rank or he has to allow another outflanking by 6....Ka6; 7.Kc5.
This way you'll always be able to advance to the other side, just like in the previous variation.
If Black takes the virtual opposition by playing 3....Ka7, you're allowed to continue moving forward using the outflanking move
In this position Black has two options.
1: stay on the a-file.
As long as black stays on the a-file, you can make forward progress (4....Ka6; 5. Kc5, and now Black has to retreat because 5....Ka5 would run into 6.Ra1 mate).
2: return to the b-file.
Whenever Black returns to the b-file, you'll be able to take the opposition on the b-file and another outflanking maneuver will soon start (4....Kb8; 5.Kb4, Ka8; 6Kc5!).
The rest will play out as in variation nr.1
This position illustrates why opposition and outflanking are important.
If you're White, you'll only win if you have the opposition. You'll win using an outflanking maneuver.
Black has two options here: stay on the seventh row or retreat to the eighth row.
If Black plays1...Kb7, you'll now easily find 2.Kd6!
Making forward progress by outflanking your opponent. After 2....Kc8, you'll take the opposition with 3.Kc6!
You're ready for another outflanking maneuver. 3...Kd8; 4. Kb7, and your king covers the queening square.
Thanks to your knowledge of opposition and outflanking, you now cover the queening square and your pawn will promote.
We've seen Kc8 in the previous line, so let's now look at 1...Kb8.
We know that taking the opposition is good, so 2.Kb6 is fine. (2.Kc6 wins as well, because after 2....Kc8; 3.c5 you'll have the opposition again)
You know what will follow, don't you? You've seen it all before....
3....Kc8; 4.Kc6, Kd8; 5.Kb7, covering the queening square with help of the outflanking maneuver.
So I hope you've got the feel for outflanking now. I think it will prove helpful in your endgames. You now know how to outflank your opponents!