I decided that it is worthy to explain how things work here, 'cause I know it may be not so clear at first.
Normally any clan's profile is updated withing 12 hours after the war end. And it won't be updated at all if a clan doesn't war. But there are rare cases when it can take longer - for instance if the official API is down or just something went wrong on our side.
If during an update a clan is caught with public war profile its losses and ties are recorded. Moreover they are going to be updated since that moment even if the clan's profile becomes private. Losses and ties are displayed as usual in such case if that clan keeps winning. But after their first loss or tie in such state losses and ties will be groupped together and displayed like this for instance: ≥ 13. They are groupped because we can't distinguish new losses and ties in this case anymore. And ≥ sign means that the real number of losses and ties can actually be greater than the one we display. The deal is that there is a chance that some losses or ties can be missed from tracking. This can happen in the case if the clan loses 2 or more times in a row and these warlogs were not found. Note that for a good war clan it is quite a rare possibility - so for well performing clans expect their losses and ties to be accurate. Also if a clan with approximate losses and ties is caught with public warlogs again - its losses and ties become accurate again.
All warlogs that are found in public clan profiles are recorded. Later they can be displayed for both participants of the war even if they both will have their warlogs set to private already. Last 2 wars are removed from displaying for private clan profiles because it can allow spying on base layouts and rebuilding these layouts for training attacks - which I consider to be really unfair.
War Map details are also found in public clan profiles but recorded separately from the main warlogs and usually don't contain the final result and score of the war. If the final result isn't recorded later you will see this war log displayed on the dark background with the inscription Unknown Result, because winner can't be detected (even though sometimes it seems obvious). And vice versa the final result can be recorded but details will be missing sometimes. Details are hidden from displaying along with the war opponent for the last 2 wars if the observed clan has private war profile settings in the game at the moment of viewing, but they will become available for viewing later.
We provide some extra stats and analysis for each war details entry, which are not available in the game. For instance, we count the amount of equal townhall attacks, which are considered hard and high quality. But instead of TH levels itself we try to estimate the real offensive and defensive townhall of the attacker and defender for this procedure. So if you are a TH10 but attack a TH11 with rushed defenses and get - this attack will be considered as TH10 vs TH10 actually. But if the real offensive strength exceeds the real defensive strength of the opponent and this attack scores 3 stars - it is counted as a dip, meaning that it was too easy to get these .
Another interesting stat is engineered bases detection. It doesn't work 100% accurately but it is designed to work better in a competitive active war. This detection is also based on the real offensive strength and real defensive strength that we estimate and usually can distinguish 2 types of engineered bases reliably: ones with engineered offense itself with specific upgrading plan and ones with the offensive strength significantly higher than the defensive strength. First type is detected reliably in all cases, the second one will depend on the opponent attacks and the war map composition. The better and the more active your opponent is or the more different types and townhalls your war map contains - the better is the detection for the second type. However, the bases with little difference in offense and defense (aka .5s) are detected very rarely. The problem is that Supercell doesn't provide the set of defensive buildings unlike troops for bases through the API yet.
Best win streak means the most wins in a row that clan has ever achieved. But an important remark should be made here: it will count win streaks that happened only after March 2016 update, when Supercell officially started counting win streaks (and even actually a little bit later because we didn't start tracking best win streak immediately after that update).
All previously achieved win streaks are lost now - sorry about that. But if you think about it - it is partly fair because along with that update came a serious game-changer which brings harder matches for well-performing clans and making achieving a higher win streak much harder. So it wouldn't be correct to mix previous win streaks with the new ones.
The timestamp when the best win streak was achieved will equal the end time of the war if war log for that war was found. If it wasn't found it will equal the time when the clan's profile was updated, which is a bit later. Timestamp is in format DD-MM-YYYY HH:MM in GMT (aka London time).
There are a number of values in your clan profile, which are not present in the game.
Level Index is a weighted-average of players' levels for a clan. Weighing puts a greater emphasis on levels of top players and lesser on bottom players. Also clans with less members will be weighted more equally than almost full clans. This value is used to "sniff" clans that can be eligible for the Reservoir Hogs League ranking.
aoBWS reads as Average Opponents Best Win Streak. It is calcualted almost as simple as you might be thinking already - We look at your opponents and opponents of your opponents (your potential war matches) and calculate the average best win streak in this subset.
aoEWS is an Average Opponents Expected Win Streak. It is similar in the meaning to aoBWS but has a clearer correlation with a probability of a clan to win. Its calculation would be too complicated to explain here, I'd only like to mention that it is also based on best win streak value and the distribution of best win streaks of all clans.
aoPoints is an Average Opponents Points and is a measure of how developed are the bases of your opponents and opponents of your opponents in wars. The algorithm for calcualting this will remain secret. I Only would like to mention that many samples are used to calculate each single value, so the random noise is cleared.
Also a little table of examples for understanding:
The leaderboard is based on the highest best win streak. For clans with the same win streak - the one, which reached it earlier will take the higher place. The logic behind this is quite simple: if your clan wants to take a higher place - you should not only reach the previous record achieved by someone already, but overcome it.
Leaderboard is live generated while clan profiles are being updated. If you refresh any of its page you may see clans go up or down (especially on pages below 5000, where things are changing faster).
if you click on the page number above leaderboard - you can input your number there to go to any page.
The leaderboard contains extra markings, which can be helpful. sign means that a clan's best win streak has recently increased. means that a clan has recently lost an increasing best win streak sequence (for clans only with 10 bws at least). The blue colored clans are known to be unbeaten yet - just an extra perk for them (for clans only with 10 bws at least). Orange colored clans are known to play in a group with a high amount of well-performing war clans and it is, for sure, harder for them to keep their win streak.
This Leaderboard is designed to filter all low level or easy wars clans and make a competition only between hard clans. To join this leaderboard a clan should have their Compound Difficulty of 80 at least. By default difficulty is calculated only for clans, which have at least Best Win Streak of 10 or Level Index of 110 at least. You can though enable regular difficulty calculation for your clan (and thus give it a chance to participate in this leaderboard) by pressing record logs & difficulty button on your clan's page (find it through the search). This procedure will also record up to 10 of your recent war logs but last 2 wars still will be hidden.
If a clan qualifies for RHL their wins will start counting towards Difficult Win Streak (DWS) value. If later this clan will be found with less difficulty than required - they still will keep their DWS value, but new wins won't be counted towards DWS until this clan regains a proper difficulty again. If a clan loses current win streak (regardless of whether they have proper difficulty at that moment or not) their DWS is reset. The best DWS for a clan is recorded too and called Difficult Best Win Streak (DBWS) and the ranking is primarily based on it.
We have started tracking DWS and DBWS values since 09-09-2016. All previous win streaks were discarded - because, first, we couldn't know at what difficulty they were reached and second, some high win streaks were achived solely by using modding constantly.
Difficulty is recalculated once a week for each clan, which has difficulty calculation enabled. You can find your current compound difficulty in the clan's profile through search. The difficulty displayed in the leaderboard is not your current difficulty but the difficulty that you had when you had reached your DBWS. It is also used as a second sorting factor for clans with the same DBWS.
Difficulty takes in account 2 factors: how developed are your potential opponents and how successful they are in wars on average. Development of the bases values more top bases on the war map and lower bases - less... Success of a clan in wars is measured with a sort of an Expected Win Streak of that clan if it would be matching with any clan in the game instead of the clans from their usual matching group. To estimate these factors we take up to 15 random warlogs in the past 2 months (partly you can see them in your clan's profile). And for each of your opponents in these logs we analyze their wars too that happened within ±14 days to the war with your clan (your potential opponents). Totally there are between 50-200 war logs used to calculate each compound difficulty value - high amount garantees us that we minimize random effects. Also it is hard to manipulate the difficulty - for instance, if a clan runs one war with TH11 players and normally does much lower level wars - its difficulty won't be affected much, because mainly the difficulty index will take in account 14 other wars and the effect of 1 hard war will be minimized. Also the fact that only your opponents are analyzed and your clan performance or development is neglected completely reduces options for manipulation significantly. So to keep a good difficulty you should constantly play with a high-level roster or if you already have a good difficulty - try to keep your roster consistent.
Threshold of 80 is chosen to approximatly target a clan that plays only with TH9-max players and have average performing opponents. So, increasingly, this leaderboard is designed to contain only TH9+ clans with some exceptions (but not errors) for lower clans, which have very hard wars due to a high amount of good opponents in their matching subgroup. Also note that since supercell now takes in account recent war performance of a clan for war-matchmaking - clans with a good performance, therefore, will have a higher difficulty value than similar clans with bad performance. I can't remove that effect from difficulty (nor I think it breaks anything anyway). If you think that your clan has difficult enough wars, but your clan's compound difficulty value is not high enough still - probably the issue is then with not enough warlogs in our database. In this case you can now request recording of logs & difficulty directly through your clan's profile to improve difficulty accuracy. In this case difficulty recalculation will succeed only if at least 2 days have passed since the last difficulty update or new warlogs are found.
This leaderboard also contains helpful markings. Generally, everything that applied to Best Win Streak leaderboard applies here too, except for Orange Clans (because, firstly, it is a different difficulty value and, secondly, because almost all clans would be orange here, which is not interesting). But we have here extra markings too. Darken and Desaturated clans have lost their eligibility for this leaderboard, which could happen due to a low compound difficulty value (difficulty will be crossed out with a red line then), not enough members for wars or clan has not been active in wars for a while. Difficulty highlighted with the dark purple color means that it is quite low and clan is risking to become ineligible for this leaderboard. Difficulty highlighted with bloody red emphasizes simply that it is indeed bloody difficult to win wars there.
And one last thing - why the hell is it called Reservoir Hogs. Well... it is a little clash adaptation of the name Reservoir Dogs, which is a cult movie from the 90s (if you haven't seen it, believe me, you have missed quite a thing). I am not sure what exactly Reservoir Dogs actually mean, but as I person who has actually seen the movie, I believe, it means just some "beasty dangerous guys". And I didn't come with this name myself, no... I stole it from some clan 😰