tl;dr: New matchmaking system makes you be always at you hard limit and penalises you if you drop few trophies because you are experimenting new deck or strategies.
As you know, the match making algorithm was recently modified so that you are now matched with people with a similar personal best (PB) trophies count. The main motivation behind this change appears to prevent people from dropping to lower arenas for the clan chest. If you do so, it will be much harder to climb back to your usual trophy count as you will mostly face people as good as you. The intention seems good but it has consequences which might be worse than the original problem. Here is my attempt to explain why.
A bit of background: I am an average player with tournament level cards with a personal best of 3300 and a second account I used very irregularly (tower level 5, 1900 personal best).
Trophy dropping is not such a big deal
I know many people complain about trophy droppers and I understand it is frustrating to be butchered by someone whose cards are of much higher level than yours. However, statistically, if the matchmaking only takes current trophy into account, for each time you will face a trophy dropper climbing back to his/her original trophy count, you will have faced a person dropping. Or, in other words, for each time you will get butchered, you will also get a free win (over the whole clan chest period).
I understand it is a more of a problem at lower arenas, but, therefore, this specific problem could be targeted instead of changing the matchmaking for everybody. For example, you could activate the new personal best based match making system only if you are 400 or 500 trophies below your personal best.
Also, clan chest is now happening once every 2 weeks, which reduces the problem.
You are now stagnating at your pre-update trophy count
So here is a reminder of how the ladder works. Your place in the ladder is mostly defined by 1) your card levels, 2) your deck and 3) your level of skill. Unless you spend a lot of money on a short term period, your card levels do not change much. At best you gain one level for a common card each week. You can change deck of course, but it takes time to find a good one and master it well enough so that you can actually climb upper in the ladder. Therefore, when you are in the 3k to 4k trophies range, your place in the ladder is mostly determined by your skills.
If you are around your personal best, you will struggle and have at best a 50/50 win ratio. Most of your wins will be 1 crown ones. That's your hard limit. If you want to go further up in the ladder, you have to either: 1) level up most of your deck cards or king tower level (takes time or money), 2) find a new deck that works better for you or 3) get more skilled (easier said than done).
Generally, when you are at your personal best, you are trying to change something and experiment in order to find a way to be better at the game and go further. This usually means you will drop a bit as you are more likely to lose some games.
With the old match making system it was not a big issue. Once you found a better way to play (involving or not a new deck) you could climb back to your personal best or beyond. If you did not find something that worked, you could come back to your old deck and play style and should be able to make it back up there (if we forget about meta shift and card balances).
The issue now is that with the match making system, you can no longer do this. If you drop a few hundred trophies because you are in a bad day or you want to try new deck, you won't be able to easily climb back because you will be matched to players the same way that if you were at your personal best. For example, my PB is around 3300. I wanted to try new decks and dropped to 3000 in the process (you do not find something that works at first attempt). The update happened and I am now struggling to stay at 3000 trophies with my old deck. If I lose trophies again trying new decks, I will again struggle to come back but I might well be stuck at 2900 or 2800 trophies (and have lower card donations caps).
Because of this, I find myself playing much less. It is hard to get some wins and, if I am in a loss streak because I am experimenting new strategies, it won't make it easier at all. It will be exactly the same as I will face equally skilled players and will therefore equally struggle to win games. I just have the guarantee that I will get stuck to a lower arena with lower card donation limits.
In short, with the current system, you are always at your hard limit. You are more likely than before to lose trophies (as always facing equally skilled player) without guarantee to be able to get some easier wins at any point.
Experience in lower arenas is not necessarily better
This is even worse with my secondary account. It is a level 5 king tower and I could push it to 1900 trophies before the update. Of course, I was kind of stuck there because I mostly faced level 7 or 8 players. Since the update, even if I dropped 200 trophies, I always face level 7 or 8 players because their PB is similar to mine. It is quite frustrating to lose many games mostly because my arrows can not one shot their much higher-levelled minion hordes. It is way more frustrating than facing this kind of situations occasionally one or two days a week because of clan chest.
Your long-term place on the ladder no longer means something
The whole interest of a ladder system is that your average trophy count (let's say in a week time frame) tells how good/bad you are at the game. Now, this is irrelevant. Unless you got much more skilled and/or upgraded a lot of cards, your position in the ladder mostly indicates where you were before the update. I could be near your personal best or, for some reasons, more or less far from it. In order to get back to your personal best you should improve a lot and get a win ratio higher than 50/50 against players also around your personal best. The higher this ratio, the more quickly you will get back there and beyond. But this will take way more time than with the old system.
How can we avoid this?
As mentioned above, the main motivation for this match making change is to discourage people from dropping trophies for the clan chest. You could therefore make few simple rules to address this issue specifically. For example:
- The PB rule only applies if you dropped X trophies in X days.
- The PB rule applies only during clan chest period and the 3 following days.
I am sure you can come with other simple rules.