because of the goals and the points.. barca winning with 1:0 will put the table this way:
1: barca 7 points all it's clear
2: dynamo kiev 5 (5-5 ga)
3: rubyn kazan 5 (5-5 ga)
4: inter 4
so before the last round between dynamo kiev and rubyn kazan it will be identical on the table ( 3-1 for dynamo kiev at home between them)
If Barca wins Rubin will have 4 pts, not 5
Here's the catch.
Lets say Rubin beats Barca and Inter draws in Kiev. The standings will look like this:
1. Rubin 7
2. Kiev 5
3. Barca 4
4. Inter 4
In the 5th round Inter will play in Barca and if they lose they're out 1 round before the end, no matter the result on Rubin-Kiev.
So, a Rubin win will be bad for Inter.
Now lets say Rubin-Barca ends with a draw and Inter draws in Kiev. The standings look like this:
1. Barca 5
2. Rubin 5
3. Kiev 5
4. Inter 4
In the 5th round Inter plays away to Barca and they might easily lose. If they lose then they'll be out if Rubin-Kiev won't be a draw. So, only a draw on Runin-Kiev will play for Inter.
3rd scenario is Barca to win by 2 or more goals difference in Rubin, or to win 2:1, 3:2, 4:3. If Inter draws in Kiev then the standings are like this:
1. Barca 7
2. Kiev 5
3. Rubin 4
4. Inter 4
In this situation, if Inter lose in Barca, then again only the draw in Kazan between Rubin and Kiev plays for Inter because if Kiev wins Inter will be out and if Rubin wins Barca will secure the first place (Barca will have 10pts and Rubin will have 7pts, but Barca will have a better h2h) and they may easily let Kiev win in the last round (Kiev-Barca).
the last scenario is a 1:0 Barca win in Kazan in the next round. Then the standings will be like this:
1. Barca 7
2. Kiev 5
3. Rubin 4
4. Inter 4
In the 5th round, even if Inter lose in Barca, a Rubin win against Kiev or a draw will play for Inter because Barca will have 10pts, Rubin 7, Kiev 5 and Inter 4, but Barca won't let Kiev beat them because if Rubin beats Inter then Barca will lose the 1st place to Rubin on h2h
Too complicated, eh?
