Im sure there was some importance to that whole scene. I just cant quite figure out how he made sure he lost the card game, so that he would HAVE to go to the Ambassadors party, even though he had to pretend he didnt really want to go.
I don't think he was able to "make sure" that he lost the card game - it was just chance. I think the significance of that scene was that the German was suspicious of him and was testing him. Since Max's "wife" (Marianne) said he wouldn't miss a card game, the German made him shuffle the cards to have some idea whether he was really an experienced card player, or whether the couple were posing or lying. He appeared satisfied after seeing how Max shuffled the cards.
shareHe wasn't satisfied after he saw max shuffling the cards. He was still suspicious. That's why he had Max write down the formul for phosphate. If he didn't know that (considering it was his job as far as the maxi official knew) them he'd none they were both full of it.
share"the German made him shuffle the cards to have some idea whether he was really an experienced card player"
Yes, but there are many, many experienced card players who can't shuffle like a Las Vegas magician. It doesn't mean anything, whether you can or can't.