Tokyo - Heading into the last round of pool games at the Rugby World Cup, only two teams have already booked their quarter-final places: England and France.

Some pools are all over bar the shouting, in others there's still all to play for. AFP looks at the various scenarios as teams strive for that last-eight spot.

Pool A 

With Ireland, Scotland and Japan all battling for two places, this is the most competitive pool.

If Japan beat Scotland on Sunday, they will qualify for their first ever World Cup quarter-final, topping the pool and probably giving themselves another crack at the Springboks -- a repeat of the "Miracle of Brighton" game in 2015.

If Ireland beat Samoa on Saturday with a bonus point for four tries, they have definitely qualified.

Scotland need a bonus-point win over Russia on Wednesday, and they must then beat Japan while preventing the Brave Blossoms from getting a defensive bonus point for losing by seven points or fewer.

There is a scenario in which all three teams finish on 15 points: Ireland beat Samoa without a bonus point, Scotland beat Russia with a bonus point and then score four tries in a narrow win over Japan -- meaning both teams get a bonus point.

In a two-way scenario, it is the team that won the match between them that proceeds. But this would be a three-way scenario where every team has won one and lost one. In this case, the two teams with the best points difference would qualify.

Currently Japan and Ireland have a much better points difference, but Scotland play bottom-placed Russia next and are likely to improve their tally.

Pool B

Pool B is pretty well decided, with superpowers New Zealand and South Africa virtually assured of taking first and second place respectively, barring miracles from Italy in their last match against the All Blacks.

A victory or draw by New Zealand against Italy puts the defending champions through as pool winners.

South Africa can all but guarantee a quarter-final berth with a bonus-point win against minnows Canada on Tuesday.

There is one extremely unlikely scenario in which all teams can end up with 15 points (South Africa get that bonus-point win against Canada, then Italy run in four tries in a narrow victory against the All Blacks).

Again, it would come down to points difference and New Zealand and South Africa are currently 115 and 70 points ahead of Italy respectively.

Pool C

Much more clear-cut. England and France have qualified, and all that remains to be decided is who wins the group. That will be fought out when they meet in Yokohama on Saturday.

The winner will play the runner-up of Pool D -- almost certain to be Australia. But the runner-up in the pool may not be too despondent as they will go into the other half of the knock-out draw from the All Blacks, meaning they cannot meet the defending champions until the final.

Pool D

Australia can qualify if they avoid defeat against Georgia on Friday. If Wales beat Fiji on Wednesday, they will also book their last-eight ticket and will need to win against underdogs Uruguay on Sunday to top the pool.

Mathematically, Fiji can still qualify but they have to beat Wales comfortably with a bonus point and hope the Welsh lose to Uruguay.

Possible quarter-final line-ups:

Saturday 19 October:

Winner Pool C (England/France) vs Runner-up Pool D (Australia/Wales)

Winner Pool B (New Zealand/South Africa) vs Runner-up Pool A (Japan/Ireland/Scotland)

Sunday 20 October:

Winner Pool D (Australia/Wales) vs Runner-up Pool C (England/France)

Winner Pool A (Japan/Ireland/Scotland) vs Runner-up Pool B (New Zealand/South Africa)