Can England hold nerve?
If, at the beginning of qualifying, England had been the position they are in now – beat Montenegro and Poland at home and they advance – they probably would have taken it.
Now that they are in the position, though, anxiety has set in, partly because they have not beaten Montenegro in three previous attempts, partly because they have yet to beat anybody in qualifying other than San Marino and Moldova, and partly because any vital game against Poland awakens memories of the goalkeeper Jan Tomaszewski’s holding England to a draw to eliminate them from the World Cup 40 years ago.
Adding to the pressure tonight is the knowledge that Ukraine and Montenegro, just a point behind, will almost certainly win their final fixtures, against San Marino and Moldova, respectively.
Third-time lucky for Bosnia?
Bosnia are already guaranteed a place in the play-offs, but they want more than that.
A play-off loss to Portugal denied them a place in the last World Cup, and the same opponents beat them again in the play-offs for Euro 2012.
Beat Liechtenstein at home tonight and Lithuania away on Tuesday and they will advance at Greece’s expense.
Until last month, Bosnia seemed to be cruising, having banged in 23 goals in six games, but they were desperately flat in losing 1-0 at home to Slovakia.
The return game in Zilina seemed to be going the same way, but the defender Ermin Bicakcic headed in a corner with 20 minutes remaining before the young substitute Izet Hajrovic got the winner with a screamer from 25 yards.
Momentum is back with them.
Who will miss the play-offs?
Only the eight best of the nine second-place teams make the play-offs (and then only after results against the sixth-place side in the group are discarded).
There are huge numbers of permutations, with no group absolutely guaranteed to have its second-place side qualify, but the two groups whose runners-up look in the most danger are B and D.
Italy have already gone through from Group B, leaving Bulgaria and Denmark to scrap over second place, while the Czech Republic and Armenia still have a chance.
In Group D, Hungary, Turkey and Romania are squabbling over second behind the Netherlands. Excluding results against the sixth-place side, 13 or 14 points should guarantee a second-place team a play-off spot.
Can Russia edge Portugal?
There is probably no football nation so underachieving as Russia, so eaten up by self-doubt, so prone to messing up what should be very simple.
So for Portugal, there is some hope. They trail Russia by a point and have home games against Israel and Luxembourg to come, while Fabio Capello’s side go to Luxembourg and then Azerbaijan.
What could have been a procession was interrupted by back-to-back defeats to Portugal and Northern Ireland. A 3-1 win over Israel last time out suggested Russia have righted themselves, but no clean sheets in four games is a worry for a team whose defensive solidity had been their strength.
If Russia do not slip up, Portugal will face the play-offs for the third tournament in a row.
Can either minnow make it?
Trinidad & Tobago, with a population of 1.3 million, remain the smallest nation to qualify for the World Cup, but two European nations could take that crown from them.
Montenegro (population 650,000) lie a point behind England and level with Ukraine in their group. If they could get a result at Wembley Stadium tonight, there is a very winnable game against Moldova still to come.
It is Iceland (population 325,000) who perhaps have the better chance of making it to a play-off.
They trail Switzerland by five points in Group E, but lead Slovenia, Norway and Albania in the battle for second. Wins at home to Cyprus and in Norway would secure a play-off spot.