Aside the different atmosphere in the champions League competition games but you also need to consider the opponents of any team before judging their performance and for the Atalanta and Real Madrid game, Atalanta normally is not a match when compared to the performance of Real Madrid this is because Real Madrid has more experience players in the champions league competition and the team has a better squad than Atalanta. Atalanta played very well but they should have won the game if not the goals they conceded very early in the second half, Real Madrid needed the win to still have hope in the champions league following their poor results so I believe they won against Atalanta to keep their hope alive and to play in the playoffs which is the best thing they could have done for a team that is not willing to lose out in the tournament this season. Atalanta played well I believe they will get better despite losing last night against a well known team in the champions League competition.