Justin Marshall: NZ needs to go low to contain Welsh centres

Yes, the All Blacks have to go low. But they also have to start more narrowly because of the lines these players run. It's the inside angle which will catch you out if you're too wide. Photo / Phil Walter

Wales have gone back to their regular centre combination, with Jonathan Davies back from injury partnering Jamie Roberts against the All Blacks.

They were also the incumbent British and Irish Lions centre combination last year. Both are very dangerous, particularly with ball in hand, and this chalkboard will illustrate how the All Blacks must counter their attacking threat.

Let's think back to that Lions series against Australia, won by Warren Gatland's team. Many might remember a bust by Roberts that led to the Wales try in the third test by Leigh Halfpenney. Davies ran the decoy line and Roberts ran a superb angle to bust through the defence and that is an indication of their strengths.

Gatland, who is of course also the coach of Wales, went into that test picking 11 Welsh players and he adopted a very Welsh approach which was based on being direct. The strengths of these two centres are their running lines, their weakness as a combination is that they are both very similar players. In fact, Davies could be a very good No12 once Roberts calls it quits.

Davies isn't traditionally a centre that goes on the outside break. However, he is still more than capable of doing so. His real area of expertise is his out-to-in running lines. Roberts also possesses that quality of angled running so in combo they provide plenty of power and bulk into the inside defensive channels.

When you have two centres that play like that, you can play flat to the advantage line. When you combine that with a third part to the equation, which will be hovering around that area in their attacking sequence -- of Alex Cuthbert and George North -- then you've got a blockbusting amount of bulk hurtling into that zone.

The most dangerous of the four, but particularly of the two centres, is Roberts. He is the most likely to offload.

The All Blacks need to go low and chop them down and quickly. There's no point in riding the tackle. It sets up a potentially entertaining and physical contest. When you have the likes of SBW in that traffic zone as well, you can pretty much guarantee there will be some carnage when they collide.

Finally, the key to this chalkboard: Yes, the All Blacks have to go low. But they also have to start more narrowly because of the lines these players run. It's the inside angle which will catch you out if you're too wide.

Usually the Nos10, 12 and 13 will line up just on inside shoulder of their opposites. In this game I think they need to give themselves a good metre or metre and a half on the inside shoulder and drift aggressively, which is more lateral than normal. It still has to be done with line speed otherwise these big players will get up too much speed and be too hard to stop. I believe the ABs can align this way and still cover the outside break.