Probably the biggest talking point, certainly in English football, is Manchester City’s situation.
They sit 22nd after a 2-0 defeat at Juventus – only one point above the places that mean elimination.
The team in that spot are Paris St-Germain, who City visit next on Wednesday. PSG beat Red Bull Salzburg 3-0 to stay in the hunt.
The loser of that game will be on the brink.
Defending champions Real Madrid, even with their 3-2 win at Atalanta, are only one point above City and two above PSG.
Liverpool, who play Lille on Tuesday, are the only team to win all their games after a 1-0 win over Girona.
Barcelona are next after a 3-2 victory at Borussia Dortmund, who sit ninth.
The Reds and Barca are guaranteed a place in at least the play-off round.
Arsenal and Aston Villa are both in the top eight after victories over Monaco and RB Leipzig respectively, along with Bayer Leverkusen, Inter Milan, Brest and Lille.
Brest, who beat PSV 1-0, are the biggest surprise of the tournament in their first season in any European competition. They have to play their home games in Guingamp because their stadium is not up to Uefa standards.
Dortmund, Bayern Munich, Atletico Madrid and AC Milan are the teams just below the top eight.
Celtic, who sit in between Real Madrid and City, drew 0-0 at Dinamo Zagreb and play point-less Young Boys next as they look to seal a play-off spot.
Leipzig, Slovan Bratislava and Young Boys have lost all six games and are the first three teams eliminated.
A thrilling finale is sure on 29 January, when all 18 games will be played simultaneously at 20:00 GMT.
