It is almost the same every season since their Alliance days. They perform well at the start of the season, then are getting worse trough out the rest of it. Some people will maybe say its because they had to play with a Standin this time but i highly doubt that the outcome would be different with Boxi. I actually think that Sumails Playstyle fits very well into Liquids playstyle and that the problem lies somewhere else.
Their biggest issue seems to be overall gameplay and competitive intelligence. First, they play the same Dota all over the year. The only one that sometimes plays different Heroes is Micke. The other 4 usually play the same 3 Heroes over and over again. They also don't change the way they play them. Liquids playstyle is basically a performance you see every day on the Broadway. From Start to End nothing changes and everyone that attends the performance can sing along after a few weeks. And as soon as they realize okay everyone figured us out they either pick something Cheesie like Brood or something weird like Omni Carry. I honestly don't know any other team that is as predictable as Liquid. If some random 3k player exactly knows how you gonna play your next game almost every single series something is seriously wrong with your strategies.
I don't know if it's a Coach issue, if it's the Captain or just the overall Team that does not understand what they are doing wrong every single season but the time for excuses are long over.