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Important information about SLeSA Rankings from 2016
« on: March 07, 2016, 08:08:49 pm »
As detailed out here previously, the Sri Lanka eSports Association (SLeSA) - the governing body for eSports in Sri Lanka consisting of senior members from all the major clans in the country, together with Gamer.LK, devised the current Ranking System as the most suitable, unbiased and fair method of ranking teams for eSports.

The SLeSA Ranking systems follows what is known as an ELO Rating system, which is an industry approved, globally accepted rating method that is used to calculate the relative skill levels of the teams involved. ELO Ratings, which were originally invented as an improved chess rating system, are currently used in professional sports such as Major League baseball and even games like League of Legends used the ELO rating system for ranked games prior to Season Three when the League system was introduced. The ELO Rating system has it's own set of formulas which assign points to each win/loss accordingly and this methodology has been improved over the years.

Why do we need a Ranking System at all?
The main reason for a ranking system to be devised was to make sure that team were not put at a disadvantage when match draws are made. A ranking system allows a proper seeding method (i.e. who is the best, who is next in line, etc) to be utilised when making a draw.

What role does Gamer.LK play in the ranking system?
Gamer.LK is the enforcing body that oversees and enforces the SLeSA Rankings. To this effect, Gamer.LK will provide official referees, rules, etc and make sure that the tournament is held to satisfactory standards.

What are ranked tournaments?
Any tournament that Gamer.LK identifies is of standard and for the performance to be judged under the SLeSA ranking system.

How does a tournament get classified as a "ranked tournament"?
For a tournament to be awarded the "Ranked Tournament" status, it needs to fulfil the following minimum criteria.
- The tournament should be open to all (no restrictions such as amateurs only, etc).
- The tournament has to be announced publicly as a ranked tournament at least 2 weeks prior to the start of the tournament.
- The draws for the tournament have to be made public before the start of the tournament.
- The draws have to be made according to the seeding method based on the ranks. The making of draws will most likely be handled by Gamer.LK.
- The tournament will have to enforce and use the Gamer.LK Competitive rules which can be found here.

What does ranking provide for a tournament?
A ranked tournament provides a certain level of guarantee that the tournament will be of a certain standard. In order for the SLeSA Ranking System to work properly, each tournament must carry a certain value with it. This value is determined by SLeSA and is used when ranks are calculated.

What do you mean by "value" of the tournament?
Lets compare two annual tournaments such as Sri Lanka Cyber Games (SLCG) held at BMICH and ABC Institute Games held at the ABC Institute's computer lab. Competitively speaking, the effort taken for a team to win at SLCG compared to ABC Institute games is completely different. Therefore, if Team A was to win both tournaments it would only be logical for them to earn a higher rank for a SLCG win, compared to winning ABC Institute Games.

This "value" assignment is handled by the SLeSA ranking system with what is known as a "k-value" being assigned to tournaments. This k-value determines the level or standard at which points for each win/loss will be determined using the formulas under the ELO rating system. This k-value is used in the calculation of the ranks, the formulas of which can be found later below.

Currently the "k-values" for tournaments are as follows:
- Online tournaments (eg: GCCL, GCDL, GCWL, etc): 50
- Small LAN tournaments (eg: Institute Cyber Games, etc): 100
- Large LAN tournaments (eg: SLCG, etc): 200

What is the starting amount for teams?
Teams start off at 1600 at the start of each ranking cycle (every two years). Teams that are unranked or newly entered at each tournament will also be assigned 1600 to start with.

So how do rankings work?
Let's take a couple of examples to understand how the ranking system works. For all these examples we will be working with 4 imaginary teams all with a starting default value of 1600 each:
Team A - 1600
Team B - 1600
Team C - 1600
Team D - 1600

Example 1
All 4 teams take part in GCDL (an online tournament).

Assume Team A vs Team B played their first match and Team B won.

Next Team C vs Team D played their first match and Team C won.

Next, we have Team A vs Team D where Team A won. Check out how the points change after the match.

So now at the end of it, the standings are:
Team A - 1604
Team B - 1625
Team C - 1625
Team D - 1597

Example 2
Now lets consider that all 4 teams took part in SLCG (a large national-level LAN tournament) instead of GCDL.

Assume Team A vs Team B played their first match and Team A won.

Next Team C vs Team D played their first match and Team D won.

Next Team A vs Team D play and Team A wins.

Next Team B vs Team D play and Team B wins.

So now, the standings are:
Team A - 1800
Team B - 1628
Team C - 1500
Team D - 1472

Lets assume now that Team C face off with Team A and Team A gives a walkover to Team C. The match is still considered as a loss to Team A.

Now lets say the finals were between Team B and Team C and Team B won.

So now at the end of SLCG, the standings are:
Team A - 1630
Team B - 1740
Team C - 1558
Team D - 1472

A couple of things to point out here:
  • A win against a team with a higher amount of points yields more points than a win against a team ranked closer to the same level.
  • A walkover is still considered as a win/loss to the two teams respectively.
  • Each match won accumulates some amount of points. Therefore a team that registers and plays every tournament and wins can still accumulate more and be ranked higher than a team that plays and becomes the champions only at SLCG each year.

How are these rankings calculated?
Herein lies the math and the calculations. There are two formulas that are used to calculate the rankings after each match.

Let us work with an actual example from the above set of teams to simplify things. Team A vs Team B plays at SLCG.

We need to first calculate their Win Probability using the formula.

So that would look like:

So Team Aís win probability is 0.5 and Team Bís win probability is also 0.5. This is mainly because they are both still on equal rating at 1600. With that they play the match. And letís say Team A won. Now itís time to calculate the new rankings using the formula.

In this formula the k-value is what we discussed earlier. Currently the k-values assigned at each tournament are:
- Online tournaments (eg: GCCL, GCDL, GCWL, etc): 50
- Small LAN tournaments (eg: Institute Cyber Games, etc): 100
- Large LAN tournaments (eg: SLCG, etc): 200

The Scoring Points in this formula can carry only 3 values based on the outcomes of the match:
- Win: 1
- Draw: 0.5
- Loss: 0

So Team A's new ranking would be calculated as:

which would result in 1700.

So Team B's new ranking would be calculated as:

which would result in 1500.

You are free to try this same calculation with a different k-value (example GCDL with 50) and see how the ratings gained/lost is different.

So what changed from this year? How does this affect the Rankings?
The above ranking system, calculations, etc have been in use from 2012 and they will continue to be used in the future as well. Now that the whole calculation and method is explained, we can move onto the actual changes that have been implemented since 1 Jan 2016.
  • All existing rankings were reset on 31 Dec 2015.
  • What this means is that all previous rankings from 2012 - 2015 were archived and starting from 2016, all teams were reassigned a starting rating of 1600 and rankings will be calculated from the first ranked tournament of the year.
  • The draw for the first ranked tournament of the year will be made based on the seedings from the previous rankings (eg: the draw for GCDL Season 10 were made with the seeding order based on the previous years rankings).
  • The current Rankings will be reset on 31 December 2017.
  • The rankings will be reset to the starting value if a team has not taken part in a single tournament within 1 year from their first tournament registration. (eg: Team ABC registers for GCDL S10 in January 2016 but doesn't play a tournament till SLCG 2017 after that, their rankings will be reset to the starting value by January next year).
  • The rankings of teams will be identified by their names.
  • Teams are categorised into two types: teams that belong to a clan (owned by the clan), standalone teams (no clan).
  • Teams that are owned by a clan are free to change their roster (completely remove all 5 players and put in a new set of players even). This will not affect their ranking.
  • Standalone teams need to retain a minimum of 3 players in their roster for the same ranking to be maintained. If less than 3 players are in the new roster such teams will be considered a new team and the starting rating value is assigned for ranking calculations.
  • Team names cannot be changed during the course of a tournament. Changes can be done only before/after the tournament.

It is our sincere hope that any misconceptions regarding the Ranking System which is implemented by GLK on behalf of SLESA is cleared. If there are any further questions please bring them up on a reply or contact any of our admins via PM.

Re: Important information about SLeSA Rankings from 2016
« Reply #1 on: March 07, 2016, 10:10:01 pm »