Other suggestions to improve collection strength algorithm in matchmaking

[Mornedil]

The current way collection strength is taken into account in rift matchmaking can be abused to gain an advantage in the matchmaking system.

Currently, it takes into account the FS of your top 20 fighters.
At a first glance, this seems to make sense since you put 20 fighters on defense in your rift.

But in practice, this can create extremely unfair and one-sided matches, because:

• The early nodes don't matter as much as the triple nodes
• A person can deliberately neglect their top 15-20 fighters to pump more FS into their top fighters.

Example:

• Player A is level 63, but never got a diamond, so had no choice but to raise all his top fighters equally since level 50 is max for gold. As a result, all of his top 20 fighters have a FS between 7k and 9k, even tho he doesn't have any fighter stronger than that.
• Player B is level 65, and has a diamond fighter at 23k FS and another at 17k FS. However, since he's focused on raising these 2, he has a few fighters in his top 20 team that's only between 3k and 5k FS.

The current collection strength algorithm considers this a fair matchup, and as a result, it can create an extremely one-sided match, where it's literally impossible for player A to beat player B's boss node, even if they play the fight perfectly.

Some real examples that has happened:

• My opponent had a Resonant Evil on his boss node with over 20k FS, with futile resistance, when my highest FS was 9k. My strongest Cerebella couldn't even deal enough damage per hit to avoid proccing Futile, making the node impossible to beat.

• Another opponent, that I've matched with several times now, has an Assasin's Greed at such a high FS that my highest DPS fighter times out even when I intercept for the entire match.

This is why it doesn't make sense to only care about the total FS of all top 20 fighters. Top 3 fighters matter the most. Top 4-9 matters more than top 10-20. Top 16-20 barely matters at all

• 3 fighters on the boss node (top 3)
  
• 6 fighters on the other triple nodes (top 4-9)
• 11 fighters are on solo or duo nodes with a single catalyst (top 10-20)
• where 5 of those are on the first accessible nodes when starting the rift (top 16-20)

Putting the same value on all of these in matchmaking, is like putting the same value on a chocolate cake and a burnt piece of toast just because both of them equal to 1 food item.

My suggestion to make the algorithm give better matches:
(both suggestions can be used together, or only 1 of them can be used, whichever would make most sense)

• Put more weight on fighter FS depending on how high they rank in the top 20.
  by that I mean, in the collection strength calculation, don't just add together the total FS of all top 20 fighters, but do something like:
  TotalFS = (top3 × 5) + (top4to9 × 3) + (top10to15 × 2) + top16to20

• Check the difference between the top 3 fighters of both players, and prevent matching them if the difference is too great.
  This will make sure both players have a more equal chance against each other's boss node.
  A possible downside to this method, is that it narrows down matchmaking even more, and might make it harder for some players to find a match. So it might be better to only use the other suggestion.

 

[Fel]

The current way collection strength is taken into account in rift matchmaking can be abused to gain an advantage in the matchmaking system.

Currently, it takes into account the FS of your top 20 fighters.
At a first glance, this seems to make sense since you put 20 fighters on defense in your rift.

But in practice, this can create extremely unfair and one-sided matches, because:

• The early nodes don't matter as much as the triple nodes
• A person can deliberately neglect their top 15-20 fighters to pump more FS into their top fighters.

Example:

• Player A is level 63, but never got a diamond, so had no choice but to raise all his top fighters equally since level 50 is max for gold. As a result, all of his top 20 fighters have a FS between 7k and 9k, even tho he doesn't have any fighter stronger than that.
• Player B is level 65, and has a diamond fighter at 23k FS and another at 17k FS. However, since he's focused on raising these 2, he has a few fighters in his top 20 team that's only between 3k and 5k FS.

The current collection strength algorithm considers this a fair matchup, and as a result, it can create an extremely one-sided match, where it's literally impossible for player A to beat player B's boss node, even if they play the fight perfectly.

Some real examples that has happened:

• My opponent had a Resonant Evil on his boss node with over 20k FS, with futile resistance, when my highest FS was 9k. My strongest Cerebella couldn't even deal enough damage per hit to avoid proccing Futile, making the node impossible to beat.

• Another opponent, that I've matched with several times now, has an Assasin's Greed at such a high FS that my highest DPS fighter times out even when I intercept for the entire match.View attachment 5737

This is why it doesn't make sense to only care about the total FS of all top 20 fighters. Top 3 fighters matter the most. Top 4-9 matters more than top 10-20. Top 16-20 barely matters at all

• 3 fighters on the boss node (top 3)
  
• 6 fighters on the other triple nodes (top 4-9)
• 11 fighters are on solo or duo nodes with a single catalyst (top 10-20)
• where 5 of those are on the first accessible nodes when starting the rift (top 16-20)

Putting the same value on all of these in matchmaking, is like putting the same value on a chocolate cake and a burnt piece of toast just because both of them equal to 1 food item.

My suggestion to make the algorithm give better matches:
(both suggestions can be used together, or only 1 of them can be used, whichever would make most sense)

• Put more weight on fighter FS depending on how high they rank in the top 20.
  by that I mean, in the collection strength calculation, don't just add together the total FS of all top 20 fighters, but do something like:
  TotalFS = (top3 × 5) + (top4to9 × 3) + (top10to15 × 2) + top16to20

• Check the difference between the top 3 fighters of both players, and prevent matching them if the difference is too great.
  This will make sure both players have a more equal chance against each other's boss node.
  A possible downside to this method, is that it narrows down matchmaking even more, and might make it harder for some players to find a match. So it might be better to only use the other suggestion.

You can abuse the system as long as there are rules in place. With your new suggestion, having a relatively similar top 20 would be more optimal. What happens to the people who decided to level and evolve only a few of their favorite characters? With this new system, they'd be matched against enemies with a balanced high FS across the board and end up making similar complaints.

What I'm trying to say is that no matter how they change the matchmaking formula, there'll be those who benefit, those who lose out and those who will try to manipulate the system.
Trying to come up with the fairest method isn't a bad thing though, its an interesting idea to have specific fighters be weighted differently.

 

[Mornedil]

You can abuse the system as long as there are rules in place. With your new suggestion, having a relatively similar top 20 would be more optimal. What happens to the people who decided to level and evolve only a few of their favorite characters? With this new system, they'd be matched against enemies with a balanced high FS across the board and end up making similar complaints.

What I'm trying to say is that no matter how they change the matchmaking formula, there'll be those who benefit, those who lose out and those who will try to manipulate the system.
Trying to come up with the fairest method isn't a bad thing though, its an interesting idea to have specific fighters be weighted differently.

not sure why you seeked out the thread when we already talked about it on the discord

It's not black or white. The formula obviously has to be balanced so that there is a middle ground, which can be done through calculations and theoretical matchmaking scenarios.

• Making every fighter in the top 20 matter equally, will put people those with an evenly raised top 20 at a disadvantage.
• Multiplying FS of top 3 fighters by 100 in the calculation (extreme example), will put those with a solid top 3, but weak top4-20, at a disadvantage.

It's definitely possible to find a middle ground, the calculation was just an example to explain what "putting more weight..." meant. Not a final algorithm (although I think the calculation is a good starting ground).

Also remember that this won't affect people in the diamond rank, since collection strength doesn't matter in diamond matchmaking. This only affects lower ranked players, where some people may have high FS diamonds, and some may not.

 

[Fel]

not sure why you seeked out the thread when we already talked about it on the discord

It's not black or white. The formula obviously has to be balanced so that there is a middle ground, which can be done through calculations and theoretical matchmaking scenarios.

• Making every fighter in the top 20 matter equally, will put people those with an evenly raised top 20 at a disadvantage.
• Multiplying FS of top 3 fighters by 100 in the calculation (extreme example), will put those with a solid top 3, but weak top4-20, at a disadvantage.

It's definitely possible to find a middle ground, the calculation was just an example, not a final algorithm.

Also remember that this won't affect people in the diamond rank, since collection strength doesn't matter in diamond matchmaking. This only affects lower ranked players, where some people may have high FS diamonds, and some may not.

Gotta have some activity on the forums after all

 

[Mornedil]

With this new system, they'd be matched against enemies with a balanced high FS across the board and end up making similar complaints.

What I'm trying to say is that no matter how they change the matchmaking formula, there'll be those who benefit, those who lose out and those who will try to manipulate the system.

I wanted to clarify why this isn't true, so to better illustrate the difference between the suggestion and the current system, I wrote a small program that can calculate the difference.

The "total" value listed at the top takes into account the multipliers on the right side.
The list of numbers below that, are the FS of the player's top 20 fighters.



A quick glance at the individual fighting scores of both players should reveal that player 2 has a huge advantage.
The weighted algorithm recognizes that, and puts player 2's total score at a higher level, so that they will be matched with someone closer to their strength.
Without the weighted algorithm, these 2 players have the exact same total FS.

If Player 1 later gets some good diamond fighters, his top 10-20 being higher than Player 2's will also be recognized:
(the only difference in the image below, is that Player 1's top 3 fighters have been buffed to match the top 3 of Player 2)


Edit:
(apologies if this is a bit over the top, I just thought putting it into a practical example would help illustrate the difference)

 

[BallotBoxer]

For me, the math is difficult to grapple, but to put it in visual terms, the match-maker needs to observe collection "shape." As in, some people's collections can be spiky mountains while other's collections are flat plateaus.

For a while I stagnated at having a group of golds stuck at 50, so my collection is mesa shaped. A homogeneous spread of experience, like butter over toast. No one is maxed-out, few have Marquee Abilities, with everyone raising slowly together. Paired with someone with a small crew of max diamond, max MA monsters, it is like a steel spear vs. a tin foil shield.

 

[WaveofShadow]

This is something that's been discussed a fair amount in the discord. I do like the idea of the suggestion on how to fix the issue---my concern is more along the lines that maybe this only affects some unlucky few and so won't have any reason to receive real attention.

It just feels really awful that I'm being punished and can't progress because I didn't receive a single diamond until lvl 57 or so and wasn't able to evolve one until 62.

 

[WaveofShadow]

Reading @Yujipooji s post on high level rifting, I have come to some understanding that perhaps we are the type of player that were complaining about rifts in the way that made them add collection strength matchmaking to begin with. (I was not yet playing at the time though).


I absolutely understand the point of rifts being purely elo based but in a game where its possible to gain advantage purely based on luck or the money/time you spend, a sole elo ranking system becomes far less accurate and fair.

I don't mind if the matchups aren't 100% fair, I don't think that's a realistic expectation, but my question similar to my above post is, are we expected to not be able to progress until we acquire a collection that allows us to do so under the current system? if we want the elo system to be the only matchmaker this doesnt work (as collection strength does not equal skill level) but it also doesn't work under the current system because as stated above even people with equal collection strengths in theory are not equal.

 

[Fel]

Reading @Yujipooji s post on high level rifting, I have come to some understanding that perhaps we are the type of player that were complaining about rifts in the way that made them add collection strength matchmaking to begin with. (I was not yet playing at the time though).


I absolutely understand the point of rifts being purely elo based but in a game where its possible to gain advantage purely based on luck or the money/time you spend, a sole elo ranking system becomes far less accurate and fair.

I don't mind if the matchups aren't 100% fair, I don't think that's a realistic expectation, but my question similar to my above post is, are we expected to not be able to progress until we acquire a collection that allows us to do so under the current system? if we want the elo system to be the only matchmaker this doesnt work (as collection strength does not equal skill level) but it also doesn't work under the current system because as stated above even people with equal collection strengths in theory are not equal.

There are ways to gain an advantage without raising your FS. The most obvious way would be catalysts. This requires a bit of luck but the fact that you need to play rifts (or spend theo) to get them is a nice touch imo. Another way is to raise your move stats. This means you'd want to do dailies regularly for coins and moves with good stats. Lastly is to get new fighters to be able to counter certain nodes.

Since these aren't considered for matchmaking, there's always a chance for a match to be unfair no matter what kind of Fighter Strength algorithm is used.

I guess the main point would be to develop a matchmaking system where there are the least amount of complaints. People will generally look at the FS of boss nodes so I think @Mornedil's suggestion isn't a bad idea, even if there are still ways to exploit it.

I think rifts isn't supposed to be a gamemode where skill is the main deciding factor. We can probably look forward to PvP for that.

 

[Mornedil]

I think rifts isn't supposed to be a gamemode where skill is the main deciding factor. We can probably look forward to PvP for that.

I completely agree with this, rifts are more about making progress to your collection, whether it's fighters, catalysts or moves. And then of course tactically using them in the best way possible.

I guess the main point would be to develop a matchmaking system where there are the least amount of complaints. People will generally look at the FS of boss nodes so I think @Mornedil's suggestion isn't a bad idea, even if there are still ways to exploit it.

It's what I was trying to go for with the suggestion, making an improvement for the current system to adjust it into being as fair as possible for minimal amount of complaints. My suggestion isn't just because I think it will personally benefit me, I really do think it would be an overall improvement to the current system.

Spoiler: Unnecessary over-explanation

Personally, I had better matchmaking when the game didn't care about collection strength at all.

With the old system, I had some matches from time to time where i was completely outmatched, but it was usually against a higher rank, so if I lost those matches, i only lost about 10 rift rank points.

Now, almost all my matches are against people in a lower rank than me because of collection strength matching, even tho they often have a couple evolved diamond fighters. So I'm not only outmatched, I also lose 20 points due to the rank difference, and if I somehow manage to win, I gain only 10.

I do understand the issue with the old system tho. People decay in rank from inactivity, and when they start playing again they match with some poor low ranked player who sometimes can't even beat the first node. So I would never suggest to bring it back even tho it would benefit me at my current rank.

 

[Luke]

There are ways to gain an advantage without raising your FS. The most obvious way would be catalysts.

Since these aren't considered for matchmaking

Well, why not? Why aren’t they included? They should be. So are move lvl.

 

[Fel]

Well, why not? Why aren’t they included? They should be. So are move lvl.

I assume the biggest reason would be that it constrains matchmaking too much. People are already having issues finding matches, especially if they don't live in a timezone similar to America. There's also already complaints about how powering up your fighters leads to harder matches, making it seem pointless. I assume we'd get similar complaints if matchmaking scaled off of more things.

 

[TraiP]

I assume the biggest reason would be that it constrains matchmaking too much. People are already having issues finding matches, especially if they don't live in a timezone similar to America. There's also already complaints about how powering up your fighters leads to harder matches, making it seem pointless. I assume we'd get similar complaints if matchmaking scaled off of more things.

that's true, introducing more metrics will probably mess things even more. On the other hand it's clearly evident that the current metric used in rift is far from good.I think the assumption that was made, for using an arithmetic mean as metric, is that people actually distribute "normally" the exp they gain from prize fights,dailies,etc meaning their collection will be normally distributed.
Larger set or a different metric is enough imo to fix rift matchmaking.
But the far greater problem is that due to the collection based comparison there have been created subranks inside each rank.e.g in G3 a player of lvl67 will only fight lvl 66-70 ,yeah that seems like a good thing but at the same time a lvl62 in g3 will only fight lvl60-64 meaning if someone jumps from g3->g2 and he is lvl 63 he will most probably fight other lvl63 in g2 without ever having to face not a single one of the higher lvls in each rank . In summary, it creates rank G,S,B for lvl groups and no the whole playerbase.
The previous matchmaking was optimal but needed a lot of time to sort out and stabilize,this one will never stabilize unless you make dramatically changes in your collection and really fast.

 

[Mornedil]

Well, why not? Why aren’t they included? They should be. So are move lvl.

I think it might cause problems to try to take catalysts into account.

When it comes to your fighters, matchmaking takes the top 20 fighters in your collection into consideration, regardless of whether or not you've placed them in your rift defense.

But this can't exactly be done with catalysts. There's no concrete way for the game to compare their strength to each other, and it's irrelevant what you have in your collection if you're not currently using it. The matchmaking system would need to consider the catalysts that are being used.

A big loophole with this would be that a person could remove all their catalysts except one or two that are very strong (like futile or scratching post) and in that way abuse the system into matching them with weaker players.

(at least this is my idea of why it might be hard to consider catalysts)

 

[Liam]

I'm super late to this thread - sorry!

not sure why you seeked out the thread when we already talked about it on the discord

I never would have seen Fel's thoughts if he didn't post them here.

Discord moves too quickly, so when it doubt, always re-post your thoughts in threads that spawn from Discord conversations. Even a screenshot of the conversation is fine!

...

I've read through all of the feedback here, and I've passed it along to the rest of the team. We'll make sure it's all considered. We do have more Rift Battle improvements planned for the future once the VERSUS mode hurdles are out of the way. Thanks for your patience!