Champions League group qualification permutations
Now that matchday 4 is complete, here's what each team still has to do to make the Champions League knockout rounds:
Atletico Madrid: A victory against Olympiakos on matchday 5 will secure their progress. If they lose the game, a point away to Juventus in the final round would secure their passage on the head-to-head rule.
Olympiakos: Guaranteed to go through as the group winner if they win their remaining games against Atletico Madrid and Malmo.
If Olympiakos lose at Atletico on matchday 5 and Juve win at Malmo, then Olympiakos will have to hope that on matchday 6 Atletico defeat Juve; a home win over Malmo would then send Olympiakos through on head to head against the Serie A side.
Juventus: Can guarantee their passage only by winning both of their remaining games against Malmo and Atletico. If they fail to win in Sweden on matchday 5, their task will become much more difficult.
Malmo: Must beat Juve and Olympiakos in their remaining games to have real hopes, but it looks an uphill struggle with only one win and two goals in the competition -- all coming in the same game against Olympiakos.
Real Madrid: Have already qualified and will be confirmed as group winners if they avoid defeat at FC Basel on matchday 5.
FC Basel: Two wins will seem them through. Should Basel lose to Real Madrid and Liverpool win or draw against Ludogorets on matchday 5, then the Swiss would need a point at Anfield to finish second.
Liverpool: Liverpool could win both of their remaining games and still go out. Key will be Basel's game against Real -- if the Swiss win against the group leaders then Liverpool would have to first beat Ludogorets and then win at home to Basel by more than one goal to go through on head to head. If Liverpool beat Basel by one goal, under this scenario (Basel beating Real) it is impossible for Brendan Rodgers' men to finish above Basel.
If Liverpool draw with Ludogorets, they have to hope Basel get no more than a point against Real. If Liverpool lose to Ludogorets and beat Basel it could come down to a three-way head-to-head tie-breaker for second place.
Ludogorets Razgrad: They will be eliminated should they lose to Liverpool on matchday 5, and a draw in that game will not be enough should Basel take a point at home to Real Madrid. Realistically, they must beat Liverpool to give themselves a chance of qualifying and even then they may need to take a least at point at the Bernabeu.
Bayer Leverkusen: Will be through with a point at home to Monaco, or if Benfica do not win away at Zenit, on matchday 5.
Monaco, Zenit, Benfica: Much will depend on that result between Zenit and Benfica, especially with Monaco to play Zenit too on the final matchday. Monaco cannot be eliminated if they lose to Leverkusen next time out, but Benfica will be out of the competition should they be defeated at Zenit.
Borussia Dortmund: Already through and will secure top spot in the group with a draw at Arsenal on matchday 5.
Arsenal: Need a point from their final two games to guarantee their progress.
Anderlecht: Must win both their remaining games and hope Arsenal do not pick up another point.
Galatasaray: Must beat Anderlecht next time out, and hope Dortmund beat Arsenal. It could then come down to a shootout between Arsenal and Galatasaray on the final matchday, but Gala would need to win by a minimum of three goals to climb above Arsenal on head to head.
Bayern Munich: Have qualified as group winners with a 100 percent record with two games to spare.
AS Roma: If Roma win the matchday 5 fixture with CSKA Moscow they will be through should Man City fail to beat Bayern. A draw in that game, or a Man City win, and second place will go down to the final day.
CSKA Moscow: CSKA would have to beat Roma by at least four goals, coupled with a City draw/defeat, for it to be possible for them to qualify on matchday 5. If CSKA beat Roma by fewer than four goals they would still need a point against Bayern on the final matchday to guarantee progress.
Man City: If they fail to beat Bayern they will be out if there is a winner in the CSKA vs. Roma tie. If City beat Bayern, and the other game is a draw, then three teams will go into matchday 6 level on five points. City could conceivably go through with a draw against Bayern and a win at Roma with six points should CSKA vs. Roma be a draw and CSKA then lose at Bayern.
Paris Saint-Germain and Barcelona: Both are through and will fight it out for the top spot, which is likely to go down to the meeting between the two at Camp Nou on matchday 6.
Ajax and APOEL: Playing for the Europa League place, which again is likely to be decided by the fixture between the sides.
Chelsea: Will qualify and secure the top spot if they win at Schalke on matchday 5; equally a point in each of their remaining two matches would do the same.
Schalke: A win over Chelsea and Schalke would only have to match Jose Mourinho's men's result on matchday 6 to go through. But if they fail to beat Chelsea in the next fixture the door is very much open for Sporting to leap ahead of them -- if that happens Schalke would have to win at Maribor and hope for a favour from Chelsea.
Sporting Lisbon: Might have to win both of their remaining games to be in with a realistic chance, though their position could be more favourable going into matchday 6 should they win at home to Maribor and Schalke fail to beat Chelsea.
NK Maribor: Will be out if they lose at Sporting on matchday 5, or if they draw that game and Schalke beat Chelsea. But a win at Sporting will bring Maribor right back into the picture with Schalke to play at home on matchday 6.
FC Porto: Are through to the last 16 and will take top spot with a win against BATE on matchday 5 if Shakhtar fail to beat Athletic Bilbao.
Shakhtar Donetsk: Remain in pole position and will be through if they take a point in that home game against Athletic.
BATE Borisov: Must win both of their remaining games and hope Shakhtar lose to both Athletic and FC Porto.
Athletic Bilbao: Have been eliminated and have only a place in the Europa League to play for, which may be decided on the final day when they host BATE.
Dale Johnson has been an editor and journalist at ESPN for 18 years. You can follow him on Twitter @dalejohnsonESPN.