There was a time when picking the All Blacks first five-eighth was a simple job but for Ian Foster it is becoming a complex task.

For a generation in the late 1980s there was lively debate over whether Grant Fox or Frano Botica should wear the All Blacks No10 jersey.

In the mid to late 1990s it was Andrew Mehrtens or Carlos Spencer while for most of the past decade the arguments started and finished with Dan Carter.

All Blacks backs coach Foster should be so lucky.

"Even today we were rotating all four of them through training and that's our goal, to have a seamless transition between them," he said after training in Cardiff yesterday.

"Traditionally you might stick with one of the tens, and the others don't really get much opportunity, whereas now, I think we have taken the philosophy that we want to give [an] opportunity to the group.

"We think that will be good in growing the others, and as a consequence we have four guys who are all pretty good in the group, and you have to say Sladey [Colin Slade] in particular [has grown]. Isn't it great we're talking about him as being one of the four because of the way he's played?"

None of which answers the question - who will start against Wales at Millennium Stadium on Sunday (NZT)?.

Carter, Aaron Cruden and Beauden Barrett are all palatable starting options as the 2014 season comes to its final test.

While Slade would be a shock, he is clearly pushing hard for a place in the match day 23.

Such depth is great but in such a key position there is a danger, for both individual and team, in chopping and changing too often.

At some point, the 10 needs to know it is his show to run.

Unlike the Fox-Botica and Mehrtens-Spencer eras, the stylistic differences between the current crop are more subtle.

Carter has been without peer for most of his career but is rusty. On the evidence of last week's efforts against Scotland he seems an unlikely choice.

If that's the case, it may be a straight choice between Cruden and Barrett.

Australia and England earlier this year before he blotted his copy book by missing a team flight to Brisbane then with some below-par goal kicking.

He can play at the line but his style is more about weighing things up, watching, then picking holes in the defensive line, often by darting around the back field.

Barrett started against Argentina in Napier and again in Brisbane but has had precious little game time in Europe with just 21 minutes at Twickenham under his belt.

He attacks the line like few others, has the size to off-load and possesses rare pace.

Cruden could be the steady choice while Barrett might be the nod to future thinking.

"Our job is to do both," Foster said when asked if selections this week would be on form or with an eye to next year's World Cup.

"It is to pick the best team for this weekend, and also have an eye for where we are going.

"There is always a bit of both, that's the truth of it, but the most important thing is what's the best team for this weekend."

- Stuff