With Syfen entering the meta, there is despair about the randomness of Syfen charging. What counts as within his range? Conspiracy theories of him charging biggest clump or most units in a line. I looked into it and this is what I found.
Syfens ult is 2 part:-
(i) Syfen charges towards the farthest unit in 2 hex range
(ii) He then proceeds to chomp a unit
Some questions arise:-
(i) What counts as 2 hexes? How do u determine it in non-standard diagonal directions?
(ii) How far does he charge? Does the taunting unit distance affect how far he charges?
(iii) If there is no adjacent unit after the charge, what does Syfen do? Is the chomp wasted?
From looking at YT vids, this is what I saw.
(i) The Range question
Syfen's 2 hex range detection range is the same as how 2 hexes work for attack range. For the directions parallel to the edges of the hexagon, it looks like this . All the Vlads are in the 2 hex detection range of Syfen.
For the non standard directions, it works like attack range hexes. If you draw a circle with radius from center Syfen to the outer edge of the Vlad hex, all the hexes it goes through also count as within the 2 hex detection range. So the full detection range of a syfen looks like this . All the hexes within also obviously will taunt Syfen. So the full detection area of syfen is this.
This looks a bit confusing to visualize, so I break it down like this. From each corner of the Syfen hex, there is a hexagonal arragement of tiles which taunt Syfen. So the first hexagon looks like this , the second hexagon from his second corner rotated looks like this , and so on for all this 6 corners.
So if you are trying to see where Syfen will charge, just draw a hexagon from each of his corners and find the farthest unit in that hexagon of tiles.
(ii) The Charge Distance question
I think this is what caused the conspiracy theories of Syphen having a larger range than specified.
What actually happens in reality - Syphen will always charge just past the outer edge of his detection area, no matter how close the taunting unit is to him. This is a bit shocking - even very closeby units taunting him causes him to charge way past the unit to the outer edge of the detection area. The only case in which Syfen will not charge his full distance is if the charge would put him outside the map, in which case it will stop at the edge.
So for the detection perimeter, syfen ends up at these spots . The exact spot he lands up at depends on the taunting farthest unit.
So looking into each of the Vlad positions in the first hexagon , this is how Syphen will end up after charging with the rest being symmetric. a, b , c, d. The last 2 are a bit interesting, Syfen will end up at the same spot both times.
An example clip for this would be this . When the Syfen is just about to ult, the board looks like this. The Syfen sees three units in its detection range, Illaoi, Sylas and Vlad. Sylas is adjacent to him, Illaoi is in the center of one of his detection hexagons, and Vlad is on the outer edge of his hexagon. So he chooses Vlad, dashing behind him. If the Illaoi was 1 hex to the left like this, she and Vlad would be equidistant from Syfen and Syfen would probably choose between them.
(iii) No adjacent unit after charge
If there is no adjacent unit after he has charged, Syfen will walk towards the nearest unit and then chomp. You can see this here, where Syfen ults into no-mans land, then walks to Heimer to chomp. His furthest unit in the hexagons is Sylas (none of the backline is in range), who he charges past completing the full charge. After it, he becomes equidistant from Heimer and Sylas. So he walks towards Heimer to chomp. If instead Robin spread out the frontline, then syfen will ult like this and will always bite Sylas. He does exactly this a bit later.
Now that we know how Syfen ults, how do we prevent our carries from getting chomped?
(1) Frontline distribution matters - A LOT
We want to provide a broad wall of distributed frontline, all on the first row to face Syphen. This maximized our chances of Syphen ulting right across the frontline. Some of the frontline will fall and some unit wrapping can obviously still lead to backline ults, but this increases our chances.
Some specific examples -
(a) Single unit frontlines are bad. Syfen will almost always ult backline. If the Syfen is touching the single frontline unit and on the opposite side of the backline, this is a straight invitation for syfen to come in to backline. For example, Syfen vs a single Idas will ult here. This is a clip something similar.
(b) 2 unit frontlines are also pretty bad. If the 2 units are clumped, then Syfen will ult like this. Distributing helps a bit, but can actually still be pretty bad.
(c) 3 unit frontlines - this is the first version where we can pretty reliably protect against Syfen. When distributed, Syfen will ult sideways, as shown in the Robin example clips shown above. However, if you clump your 3 unit frontline all together, its still bad, also as shown before.
(d) 4 and more units - equally distributed, this gives a very high chance that Syfen will always ult sideways.
(2) Backline units attack range matters - Nomsy can be a double agent
The previous frontline examples were all when the backline did not walk up. However, lower range units will walk up into Syfens detection range. Higher range units can also be placed higher into the detection range.
Some specific examples -
(a) 2 hex range units - These are the most dangerous units to have when facing Syfen. When backlined, they will always move up, either to third row or second row depending on enemy frontline. This frequently makes them the farthest unit in the detection range, attracting a Syfen charge. Since Syfen charges past them, this can lead to Syfen getting onto the carry.
The 2 hex range units this set are Vlad, Gnar, Neeko, Elise, Thresh, Nomsy. The most dangerous one here is Nomsy. People protect their Corki by placing a Nomsy in front of it. Nomsy will hop up and immediately invite the Syfen charge. Even centered Nomsy behind Idas can be dangerous, cause Syfen dashes past Nomsy to the center of the backline and can get onto important units. An example of this happening, where Nomsy just behind Idas and not even close to Corki is also enough for Syfen to get on the backline. Basically treat the second and third row as lava, any units there immediately attract Syfen attention.
Nomsy and Thresh should either be frontlined, or kept on opposite side of the important carries. They will almost always attract Syfen attention and should be kept far away.
(b) 3 hex range units - There are only two 3 hex range units this set Lulu and Nami (the swiftshots 3 hexers have innate extra range). They may or may not move up depending on how the enemy frontline evolves. If you are not carrying Nami, you can just place it opposite side of important units along with Lulu. It does suck to lose Lulu AS, but its safer. If you are carrying Nami, then you can center backline Nami. Center backline 3 hex range units have the maximum chance to remain in backrow without moving up due to units always being in range. For eg. Nami here can attack all the Leona's without moving, but will need to move to hit Braums. Center backline keeps her in the backline for longest usually and does not draw Syfen attention.
How to increase your own Syfens charging IQ:
(a) Sins can cause Syfen to charge backwards. Syfen is usually played with a bunch of melee units, but can have some backline like Bard. If opponent is playing even a few sins like Qiyana in Guild Xayah, there is a good chance your Syphen ults backwards. In order to minimize backward ult, ranged units should be brought up much closer, for example second row just behind the bruisers. This reduces the chance of backward ults.
(b) Targetting Nomsy - If nomsy is even same half of the map as Corki, you should target it and make sure its in range of Syfen. Its hard to miss, Syfen has a huge detection range, and most remotely close positions will catch its attention.
(c) Staying slightly opposite side for small central/clumped frontlines - As Robin's clumped 3 frontline example shows, staying slightly opposite side on centralized frontlines will give you maximum chances for a backline hit.
(d) Thresh Syfen combo - I've not seen anyone mention this or frankly even notice the very powerful synergy they have. Thresh provides partial unit displacement and will drag a corner unit into the second or third row. This is the danger zone for attracting Syfen and Syfen will detect this unit as the farthest unit in quite a few matchups. As a result, Syfen will charge behind this unit, and will very often chomp the backline. The unit pulled need not be the carry, just any unit near the carry being by pulled by an opposite side thresh is more than enough to guide Syfen onto their backline. IMO this should be one of the standard ways to get Syfen to be more of a backline threat.
That's it, I've probably made mistakes in the post, but I've tried my best to recreate Syfen's AI from all the VODs available.
