Guild Wars 2

Looking at the algorithm and wanting to understand it, I have some questions that a dummy like me would be very appreciative if answered.

I. What do these terms mean:

1. falloff
2. RosterSize Distance
3. Rank Distance
4. Rating Distance
5. roster
6. team
7. roster.countProfessions(profession)
8. team.countProfessions

II. I don’t understand the following code. Explain, plox:

def pickRoster(team, maxLadder, maxRosterSize, potentials, config): #idk what this is
best = None
playersNeeded = config.teamSize – team.players
for roster in potentials:
if roster.players > playersNeeded: #please explain this
continue
roster.score = scoreRoster(roster, team, maxLadder, maxRosterSize, config.scoring)
if best is None or best.score < roster.score:
best = roster
return best

III. How is team and roster rating and rank calculated?

ty in advanced, to anyone who tries to tackle this for me.

Where did you dig dis up?

From what I can tell, just glancing over it without going into detail:

def pickRoster(variables) defines a function, which can be called. It simply says “this following section is a function, which can be used by calling it and supplying it with the variables in the brackets.”

for roster in potentials
is basically a for each loop. You take the list variable “potentials”, which contains multiple rosters and go through the list one by one. The currently selected roster is stored in the variable roster.
Explanation:
FOR – loop function
ROSTER – loop variable
in – how to get loop variable
POTENTIALS – list, where to get the individual roster variables from.

For each of those rosters, the function
if roster.players > playersNeeded: continue
is checked. It simply checks, whether the roster size of the currently checked roster is larger than the required players and if yes, it calls the continue function, which jumps right back to the loop head and starts over with the next roster.
If not, it skips the “continue” and goes right on to examining, whether the roster is a good fit.

I’d advise you read a bit about programming. Especially about loops and conditions, it’s all pretty basic.

Roster size is the number of people in a premade party. The distance would be the difference in the size of premades between the two teams.
Premades add something like 2% rating per person in the party.

Dont bother trying to understand it, it doesnt work

Disclaimer: I’m still trying to boil it down to as little terminology as possible, without using tens of different technical terms, so someone, who knows his stuff: When reading “variable” just insert the correct term in the current context, be it object, attribute or whatever.

the dot operator basically means either:
Access the following function from the variable.
roster.countProfessions(profession)
In this example, roster has a function, which counts, how many of a specified profession are in the roster.

or:
Access the following sub-variable from the variable.
roster.ratingLow
In this example, I’d assume, it’s just the lowest rating amongst all players of the roster. Might also be the lowest rating, the roster can ever be matched with. Read the context and find out.

Basically, the dot just tells the program to “go deeper” and access information stored within a variable.

That being said, you can now begin to look through the source again and connect the dots yourself. (stronk pun!)

For that, I’d need to read the whole algorithm, which, tbh, I cba doing.

I’ve seen way worse code. It’s readable and can be easily understood. At least, you aren’t dealing with an abc-programmer or a three-star-programmer here.

Evan Lesh.3295:

When we are gathering up rosters to make a team, we don’t compare mmr directly, we compare the worst-case scenario of their mmr: ratingLow. This is glicko rating minus glicko rating deviation.

http://www.glicko.net/glicko/glicko2.pdf

Why wouldn’t you include the rating deviation?

Evan Lesh.3295:

Jasher.6580:

Evan Lesh.3295:

When we are gathering up rosters to make a team, we don’t compare mmr directly, we compare the worst-case scenario of their mmr: ratingLow. This is glicko rating minus glicko rating deviation.

http://www.glicko.net/glicko/glicko2.pdf

Why wouldn’t you include the rating deviation?

When I said ‘minus’ I literally meant a subtraction. We assume players with ‘unsure’ ratings are probably on the less-skill side. As mmr becomes more accurate, that difference becomes very small.

Okay understood. Good deal.

so matchmaking is done using voodoo

splains a lot

Evan Lesh.3295:

When I said ‘minus’ I literally meant a subtraction. We assume players with ‘unsure’ ratings are probably on the less-skill side. As mmr becomes more accurate, that difference becomes very small.

So, hang on. If you have a high rating and start winning over 50% of your games, your deviation will increase because you’re winning. So does that mean, if your deviation increases by more than your rating changed, your MMR effectively goes down?

Merus.9475:

Evan Lesh.3295:

When I said ‘minus’ I literally meant a subtraction. We assume players with ‘unsure’ ratings are probably on the less-skill side. As mmr becomes more accurate, that difference becomes very small.

So, hang on. If you have a high rating and start winning over 50% of your games, your deviation will increase because you’re winning. So does that mean, if your deviation increases by more than your rating changed, your MMR effectively goes down?

I don’t think you understand what deviation is. Deviation is the amount of uncertainty, a player who is fairly new or constantly gets unpredicted match results will have a large deviation.
If your deviation has settled, both your MMR and deviation will move very slowly. Your deviation will move slower than your MMR since the system will assume you’re just having a lucky run (which is the whole point of the glicko system).