The Dyrus/Superman leash makes your jungler take basically 0 damage while starting their jungle route, but does it really make a difference in their performance?
The so claimed "Superman leash". You can see the how to and comments of it in the video below.
As you can see, the trick is quite simply. You walk from left to right, the mob will try to reach you from the shortest distance possible and wanders back and forth. This is a bug of logic but this is not what we are talking about here.
The point in doing this kind of leash instead of normal leash
The leash is very helpful independent of the type.
In the normal one hit leash you don't do any damage, so what's the point?
Your help in normal leash is to AVOID EXTRA DAMAGE TO THE JUNGLER.
Following this logic, your jungler can clear the red/blue camp, that should have left him/her below 50% health (sometimes only with 10%), without receiving too much damage and give him/her the opportunity to stay in the jungle longer or even make an early gank with more health/resources.
Should I always do this kind of leash for the jungler?
Always is never good, but the answer is "as much as you can". You can also perform this kind of leash when the jungler is at blue to get the double golems by red.
But the time I'm going to lose minions at this rate
You probably are going to miss some minions (2, maybe more), but the advantage you give your jungler is huge.
As I said before, you create a window for your jungler, where he can do tons of things:
This type of leash should only be done if your jungler intends to counter-jungle or gank after the initial clear. Otherwise, all viable junglers do not need this leash in order to complete a normal clear.
A recent example seen a lot is with Dr. Mundo, where teammates will damage Blue such that Mundo does not need to use Smite in order to clear the camp. This allows him to run straight to the opposing Red Lizard camp and quickly steal it.
Few junglers are able to gank immediately after a full clear with double buff due to being low on HP, however, with a Superman leash, junglers can clear with near-full to full HP and gank immediately with double buff intact (more importantly red buff).
Yes. It makes a HUGE difference. If the jungler tanks it himself most jungles will go to half HP, and after they clear the rest of the jungle and get to LVL 4 that initial leash can make the jungler have 80% hp and be able to gank, or have like 30% and have to go back to base. Leashing is a KEY tactic to help your jungler help you.
Well, it's not really worth it if they just farm their jungle, but doing would allow them to not use their smite, which would let them counter jungle the enemy red/blue buff, which could put the other jungler far behind, which could be worth the extra time leashing.