Sunday, November 9, 2014

Decoding Clash of Clan War Matchmaking Algorithm

First of all, I am not affiliated with SuperCell. I am a computer programmer and a math major so I am purely coming from my own war matching experiences and what I learned from the internet. So this is a post based on my educated speculation of how the system works.

First of all, this thread did inspire me so please read this one first :
How clash of clan war matchmaking works

1. How a clan's strength is calculated
I suspect rather giving a clan one number to indicate its strength, it probably has multiple numbers in each category, such as troop strength, defense strength, spell strength, hero strength, army camp size, etc.. A number and range is assigned to each category and then normalized through geometric mean calculation.

A geometric mean is often used when comparing different items and finding a single "figure of merit" for these items since each item has multiple properties that have different numeric ranges. For example, the geometric mean can give a meaningful "average" to compare two clans which are each rated at 0 to 100 for their troop strength, and are rated at 0 to 1000 for their base strength. If a numeric mean is used to calculate the ave strength, then the shifting of base strength will overshadow the troop strength. Using geometric mean basically takes the 'weight' out of the calculation and gives a more clear picture of a clan's overall strength from all aspects.

I also believe SuperCell gives Townhall level a different weight. I agree with what this forum says that a rushed fresh TH9 will weight more than a max TH8. That explains why our clan that barely has 5 TH10 got matched up with some clans that have 20 TH10. But when you look at their TH10 bases, they were super rushed.

2. How the search is conducted
So if Super Steve says "mis match is better than no match", I most definitely agree with the speculation that the longer you search, the greater chance the mis match will happen.

See the above forum thread for more explanation. But in short, if the system can't find you a close ranged match, it will expand the circle of search and the chances of your clan being matched with someone significantly weaker or stronger will increase.

Another factor that matters in search is the pool of available opponents that share the close range of strength with your clan. Majority of the clans out there have just a handful of TH10, 10-15 TH9, 10-15 TH8 and rest with baby bases. The bases and troops strength are also spread in wide range with some maxed and some rushed. So if your clan is so strong and so out of the normal pool of ranges, you will have much less opponents to choose from, thus the chance of being mis matched simply increases because there aren't many available choices available so you must go out of your range.

3. How to build a war clan to get fair balanced matches
 I believe SuperCell does a good job calculating and comparing clans' strength. The mis-match doesn't happen during the calculation, the mis-match happens during the search.

So based on the above speculated theories, here are my guidelines as how to build a successful clan for war:

1. Stay in the normal range of strength and don't become an elite clan unless you are ready. You will have much larger pool of clans to be paired with.

2. Recruit solid TH9,TH10 and TH8 and avoid rushed or fresh bases. That's because max TH8 still gets a smaller weight than a rushed TH9. But if your max TH8 player is a better fighter and base is harder to be crushed, might as well stick with a lower number which brings down your overall strength than having a higher TH player. Rushed TH10 definitely will hurt your clan more than having rushed TH9 or TH8 so choose your TH10 bases wisely.

3. Throwing 1,2 low bases will not help. But throwing 10 will. This is especially true for our clan while we have solid 30 fighters and that's all we need to win war. The bottom 15 players's contribution will be bringing our "strength" down to a good range while we have the top 30 fighting the war.  As you can see from the calculation algorithm, 1,2 low bases won't help much, but once you throw in a large number, it will.

4. This is the most important factor : re-search after a few mins, so you stay in your range. This is more important than balancing your clan bases. So cancel the search and re-do it every 5-7 mins.

Good luck!

45 comments:

  1. Hi Kitty

    Question: does adding lower bases work? According to Super Steve:

    Update: Proof of concept of geometric mean; that adding low levels to find weak opponents is "shooting yourself in the foot."

    Quote Originally Posted by SuperSteve{SuperCell}

    Also keep in mind that clan matchmaking is based on clan composition, and not average strength of the entire clan. As such, adding lower level member to your clan will not help you find easier matches, and will backfire in the form of providing more 3 star wins for the opposing clan against the low level members.

    Seb

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  2. that's why I don't think adding a few lowers will help, but I am pretty sure adding 10 to 15 will. Doesn't matter how you slice and dice it, if the clan is consist of 30% low strength base and troops, overall "figure" has to go down.
    No, it's def not the ave strength of the entire clan. The clan composition is consist of categories such as base defense, troops lvl, spell level, heros, etc.. That in term I believe is the clan composition and if I were code the program, I would use geometric mean to normalize all these categories to calculate the clan strength. So "average" is def not to be taken literally here. I don't think it is a sum and divided by the number of bases. Rather, geometric mean equation is used.

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  3. How can we break down the values of the different defenses, troop upgrades, and TH upgrades? I want to maximize my secondary accounts to provide troop support, but still bring down the overall clan strength ranking.

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  4. Is there any differences if we drop our trophy count before the search ? Let me know . thanks

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  5. I totally agree that the longer time the search is finished, the higher possibility of mismatch and this based on our clan war experience. And most of the time, we are matched against a stronger clan/bases but whenever we defeat them its like a world cup championship celebration in the clan. ;)

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  6. Please change the font/background. This page is unviewable.

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  7. The background. Just noticed it after reading whole page.

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  8. Lol me too...background

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  9. is there an app or a website that allows me to compare bases strength?

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  10. i have a rushed TH10 in my clan,shoud i kick him or just dont take him to wars?

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  11. Rushed bases can help in your war matching but look for ppl who have troops, at least a war build, matching their th. A rusher with weak defenses and troops can hurt greatly.

    We are a clan that loves a long search and 80% of the time are mismatched with weaker clans. That helps because we have a large number of newer players who are less experienced attackers.

    Remember that the lower 75% of any clan will/should be 3 starred. Having smaller rushed bases that can attack 5 or more above their ranking can benefit your clan. You probably have a number of members who have to attack lower so it evens out. And it really messes with your opponent when your #21 3 stars their #9. :)

    And a final thought.....20% th10-9, 50% th8-7, 30% th6 & under, that's a great combination for us.

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  12. Is the calculation made considering all members in clan or only those participating in war?

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  13. Is the calculation made considering all members in clan or only those participating in war?

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    1. Only those in the war. The calculation is made the moment you start war search. If someone just got TH9 and is about to buy their queen, start the war first and have them buy their queen on prepday to take advantage of their lower weight for the search but higher weight during the war.

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  14. I got th9 but my troops is nearly max for all war troops.,
    question when all my troops max for th9 but my def weaker than max th8., in clan war match can possible my counterpart is not above th8? thanks for answere

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