Decision day at the World Cup

Never, perhaps, since even the first women's rugby World Cup in 1991 has a tournament been so wide open and unpredictable.

As we enter the final day of pool matches none of the seven teams left in cotention can be certain of a place in the semi-finals, and we really could have to wait until the last play in the final game on Saturday evening. Four of the six games on Saturday will have a bearing on the outcome.

As a reminder, the three pool winners qualify outright, where they will be joined  by the best runner-up. The criteria to decide this - and also decide the rankings of the pool winners, which will decide who will play who - will be based on:

And if all that fails, they flip a coin.

As for the draw in the final four, the pool winner with the best record will play the best runner-up, while the other two pool winners meet each other.

Pool A

This is a now straight fight betweenEngland and Canada, two of only three teams in the tournament to have a perfect record so far with two bonus-point wins each. England, who also have by far the best points difference in the tournament at +102,  will start as favourites and - if they do win - will almost certainly be the top seed in the semi-finals (only France in Pool C could, in theory, catch them - and that is unlikely).

However it will not be a walk in the park for England.

Canada beat them twice almost exactly a year ago - though it has to be contended that this was on Canadian soil. More recently, last November England recorded a decisive 32-3 win at The Stoop, a result that may be a better guide, though this game should be far closer.

The results in the tournament to date tell us little - England's points advantage is mainly based on their playing for most of the their game against Samoa with only 14 opponents.

Whatever the result it will be vital for the loser to pick up at least one bonus point - and for Canada especially ideally two.

Also in Pool A

Spain play Samoawith both teams aiming for a place in the 5th-8th play-off. Spain have shown some real strength of character in a tough pool, with tries against both England and Canada, and should  be too strong for Samoa

Pool B

The first game of the day should seeIrelandconfirm their place in the semi-finals by beatingKazakhstan. While that Kazakhstanis have shown considerable improvements in speed and all-round ability this time, after large defeats to USA and New Zealand it's hard not to see the same thing happening again. Ireland, however, will finish the pool with - at most - 13 points and will therefore be in the second semi-final regardless of scores elsewhere.

The crucial game in this pool, however, will beNew Zealand against the United States.Crucially New Zealand will know exactly what they have to do to reach the semi-finals before they play, as their game follows on from England v Canada on Pitch 1.

That knowledge - as we saw in 2010 when Australia slipped into the semi-finals ahead of Canada - can make all the difference. They will know that they just need to win, or need a win and a bonus point, and they will also know the margin of victory they will need. It will not be easy as the United States put as good a fight against Ireland as New Zealand did, and the States know that they have to win the game - because if they do they could be in the final four as well.

And given the United States' pattern of play it is entirely possible that they could create an upset - they are exactly the sort of team that New Zealand do not like playing against, and they will seize on any mistake in exactly the same way that Ireland did. Furthermore New Zealand have never, in their entire history, been in this position and we simply do not know how they will respond.

On paper we have to say that the Ferns should take this, and with the timing advantage, if nothing else, should proceed to the semi-finals. But it could go wrong for them very easily.

Pool C

France and Australiaend the day in what always looked like being a straight winner-takes-all game from the moment the numbers were drawn.

In truth though they have been very solid and scored some good tries ,neither side have quite hit their straps for a full 80 minutes.

France have a perfect record, with two bonus wins, but without huge fluidity, mainly because the perhaps their beat team has yet to be selected.

Australia have failed to pick up try bonus points in either wins - which is a flaw that was maybe hinted at in their warm-up game when they failed to score any tries at all. That may be the difference in the end, and - with the added advantage of a home crowd - France should take this.

They will probably not win by enough, however, to be the top seed in the semi-finals, so they (or Australia, if they cause a minor upset) may be looking at a final four game with Ireland.

Elsewhere in the pool

Wales take on South Africa with both teams having a lot to prove. Wales seem to more confident, overall as the Springboks have been deeply shaken by the loss of their captain who will still be missing from this game regardless of the outcome of any appeal. Wales should pick up their firsr win, and with it some revenge for their defeat in 2010.