Ranked Duo and Squad current point calculation & planning
Hello dear Lumia Survivors!
Today we’d like to share our current point calculation method for Ranked Duo and Squad, along with our future plans for it.
Note: This article contains boring math and numbers, so if you’re not into that, you can just skip to the part titled “Future Plans”.
[h2]Conditions[/h2]
Before we begin with the details of the Ranked system, we would like to go over some of the conditions of the Ranked system.
[h3]Elo System[/h3]
Most games these days use Elo as a basis for their Ranked system.
Elo is known to be a very reliable way to measure game performance, among other existing methods.
The basic principle of Elo is to compare the expected score of winning (E(A)) versus the actual score (S(A)) of person A against B when person A fights person B.
By using the basic formula of S(A) - E(A), a correction value will be added.
S(A) gives 1 point if you win and 0 points if you lose.
E(A)is the expected probability calculated as a decimal point. It’s calculated by the difference between the Elo score of A and B, if they have the same performance (score) they receive 0.5, which means they each have a chance of winning of 50%.
If E(A) is 0.7, it means that A has a 70% chance of winning against B.
When E(A)=0.7,
if A wins, it gets 1 - 0.7= +0.3 points,
if A loses, it gets 0-0.7 = -0.7 points.
This was a very brief explanation of the system, but if you’re interested in knowing more about it, you can check the Wikipedia article below for more details, notably under the section "Mathematical details".
https://en.wikipedia.org/wiki/Elo_rating_system
The main characteristic of the Elo System is that the relative relationship between A and B is always set.
Therefore, Elo cannot be applied to indicators that do not establish a relationship between A and B, such as damage or crafting.
The Eternal Return Ranked System uses almost the same variation of the Elo System for both "kills relationship" and rank.
We also want to talk about the biggest part in this system: the current method of how Duo and Squad apply a “Kill relationship” and our future plans for it.
[h3]Sharing Team Score[/h3]
Eternal Return shares team scores to get the scores of Duo and Squad modes.
Kill relationships occur between individuals such as “A slain B”.
However, Duo and Squad are team games, so we need to get an estimate for teamwork or sacrifices.
If you turn Kills into personal scores, roles such as 'tank', who may die a lot, or 'support', who may struggle to pick up kills, can become ambiguous.
Before the teams gather, there may also be kills or deaths. This may be because of their own play, or the joint responsibility of the team that didn’t gather quickly.
Since the sacrifice of a team member is a play that needs to be well rewarded, the base score System for Squad should become a team score.
We also like to talk about the assumption that the team will share the score of "Individual Kills" and the negative score of "Individual Deaths" equally.
[h2]Types of Kills relationships[/h2]
The Kills score for Duo/Squad gets a little complicated because of the “downing” of players.
We have different methods to calculate scores and determine whether “downed” players are seen as kills and “full kills” are seen as a kill.
[h3]1. Seeing a “full kill” as a kill[/h3]
[h3]1-1. Team extermination score (Current System)[/h3]
In the current Duo and Squad modes, Kill scores are not individual kills, but rather “team kills”.
Once you kill the last player of a team, the relationship between the teams is established and Elo is applied.
The team kill score is, to some extent, the strength of the estimation of the team play. For example, even if two people die early and end up funneling items to one person in the squad, if one person pays off, it should still be rewarded.
If a tank engages and dies, but the team wins, the contribution of that tank will be properly recognized.
However, the problem with the team kill score is that even if you full kill the team and miss one enemy, you’ll miss out on points.
Experience and items from a full kill victory increase your chances of winning and indirectly increase your chances of scoring.
However, if that person missed is slain by a different team, your team cannot receive those points - thus limiting our current system.
We kept using this Team Kill score, however, as it has less side effects overall compared to other methods.
[h3]1-2. Individual Kill Score (Downed→ death) [/h3]
Simply put, it’s calculating a kill of one person who goes from a downed state to a full kill state.
This method has two big problems.
The first is that vultures and… rats can gain a big advantage. For example, if you down two players and another squad comes late and cleans up, they get all the points.
The second is that it induces the strategy of finding people early in the beginning. The strategy to cut off a person in Squad is a powerful tactic. If a personal kill score is introduced, there is concern that the squad meta will evolve into all three team members starting together in the same area from the beginning.
[h3]2. Marking downed player as kills[/h3]
Calculating “downed” as a “kill” is a bit more complex.
[h3]2-1. Problem of a repeated “downed” state[/h3]
If you process the kill relationship when downing an enemy, you can receive Kill points many times while going back and forth from a downed to an alive state.
The problem isn’t even solved by introducing a system like whether you receive Kill points once from downing a player or if you get them every time.
With the Elo System, the Kill points are, no matter what, the same as deaths. And since Deaths = minus points, Dying repeatedly becomes a bigger problem than getting multiple kills.
If a person is downed twice, the second time is recorded as Death, resulting in a point decrease.
In other words, for MMR, it is the most reasonable strategy -- except for the case in which the first-place squad gives up without reviving once they’re downed.
This is why, when “downing” is included in the kill relationship, we should check it only once.
[h3]2-2. First downed[/h3]
How about we count only the first down as points?
In this case, a person that has revived once cannot get more kill points. (Kill points and Death points are similar in the Elo System).
This would mean that even if they almost fully kill the enemy squad, the team will not be able to receive points if all the members from the enemy squad are revived by the later part of the game.
[h3]2-3. Last downed[/h3]
On the other hand, how about we count only the last downed as kill points?
In this case, there comes a problem of implementing a cut off meta, similar to the full kill score of (1-2) because it's always better to kill someone than downing.
On top of that, it causes a technical dilemma because there are many cases in which you can only know the “last downed” after finishing the game.
If someone is downed while your team is full killed, we need to settle our team’s MMR - but we don’t know if this person has been revived. We may not even know until the end of the round.
When calculating MMR beyond the boundaries of a single round, the next round must begin with a changed MMR, all players participating in the next round have to wait to calculate their score.
Because MMR is not fixed within the game server, this structure can perhaps weaken the security of the game.
To avoid this, the slain squad should not be able to shift ranks until the winner is determined but we believe this wouldn’t be a good experience for players.
[h2]Future Plans[h2]
It’s hard to find the right answer for calculating Kills because of the technicality and complexity that affects the meta of Squad/Duo.
First of all, our goal priority is to show the “team kill” count and individual count in order to make the current team kill score clearer. In addition to the existing K / A / H, "Wipe", meaning full kill, will be displayed in Duo and Squad.
In the long run, the most likely method is to calculate the first downed score and combine it with the existing team kill score.
The most unfortunate part of the current System is that at the end, when the match is 3 vs. 2, there is little merit for the 2. If the disadvantaged team picks up a kill, even if they lose in the end, the last battle will be more meaningful.
Of course, there will also be different limitations to this plan.
The ranked system is one of the most important factors for a fair game, and we believe that we should continue to think deeply about it and find a reasonable way to fix it in the long run.
We appreciate any good ideas or feedback about the detailed measures that we could take regarding the Kill score.
Thank you!
