There are many teams that perform well against strong teams and perform poorly against less strong teams. Sometimes strong teams do not know the past analysis of weak teams and their players in detail so during training, the match situation goes against them due to not knowing the strengths of the opposing team players. If they were aware of other strong teams and their players in advance and practices their strategies to counter them in advance it would be easier to play against them. The same situation was seen in the case of Barcelona, they performed poorly against Rayo Vallecano. But despite being a weak team played very well because the Vallecano players were aware of Barca strengths and went to the field after studying the players of the opposing team.
Strong club realize their opponents are weak, so they field second-string players without realizing that the weaker clubs have made changes in their game plan and also different players when entering a new season, so the strong clubs conclude they are still weak. Well, this is what often causes surprises when seeing strong clubs play weak clubs, meaning they have underestimated from the start without thinking the weaker club will make it difficult for them.
This is a lesson for strong clubs that they really need to pay attention to changes that occur in weak clubs to avoid making mistakes that can prevent them from getting full points.
Bro studying players or not studying players makes no difference the fact is Rayo Vallecano was just fortunate to have gotten a point out of them and Barcelona game, we all know there's no way Barcelona can go unbeaten in the Spanish LA Liga the defeat might come from a strong team or a weaker team the thing is the Spanish LA Liga has gone beyond where a team can go unbeaten if something like that should happen it should be long ago, now let's wait till their second meeting if Rayo Vallecano can get a draw, because if we should talk about studying a team even the strong team also study they weak teams but still lose or draw.