Cricket: Black Caps moving into winning position

Kane Williamson and Tom Latham saw New Zealand safely through to stumps on day three. Photo / Getty

Now it's time for some calculations, as New Zealand look to plan their march to victory at University Oval over the next two days.

They will start the fourth day against Sri Lanka at 171 for one, leading by 308, and they'd be smart to take a glance at tomorrow's weather forecast which near guarantees some afternoon rain.

There's an old school line of thinking that you shouldn't take the weather into account - stick to your plans and if it gets wet, so be it.

But in this case, with New Zealand so dominant, they can afford to pull out earlier than they might against, say, India or Australia with their batting muscle.

Kane Williamson hurried things along late today, having reached his 1000 runs for the calendar year - the second New Zealander to the mark, after Brendon McCullum's 1164 last year, and fifth player this year after Englishmen Alastair Cook and Joe Root and Australians David Warner and Steve Smith.

Tim Southee and Trent Boult will likely mark out their run-ups by the start of, or very early in the middle session tomorrow, if not shortly before lunch.

A lead of 400 should be sufficient but they would want five sessions, or the best part of, to dismiss Sri Lanka.

The pitch remains comfortable to bat on, other than the scuttling delivery from Rangana Herath which darted through very low to bowl a bemused Martin Guptill in the final session today.

"We know we'll have our work cut out when comes time to bowl," senior seamer Southee said. "It is still a reasonable track, as our batters have shown.

"It's definitely not going to come easy. [If] batsmen get in on this wicket, there are not too many demons in it and we are going to have to work extremely hard to take 10 wickets. The new ball is going to be crucial."

New Zealand's day today began as well as could have hoped, with Southee whistling through overnight pair Dinesh Chandimal and Kithuruwan Vithanage inside his first nine deliveries.

Allrounder Milinda Sirawardana, easily the highest scorer in Sri Lankan domestic first-class cricket this year, looked good. In Herath he found a doughty defender.

Herath took plenty of punishment, notably from Neil Wagner going around the wicket and pursuing a short-pitched policy aimed at Herath's body. Southee clattered the back of his helmet, too, which in these post-Phil Hughes days always brings concern.

Wagner's only offside fielders were two slips and a gully, with the other six sprinkled around the onside. Just before lunch, Wagner had all nine fielders on the offside to tailender Dushmantha Chameera. Perhaps it was a bucket list wish before the skipper moves.

There were some oddities about Sri Lanka's bowling strategy, too. Quite why captain and military medium pacer Angelo Mathews opened with himself, and the buffeting north-easterly at his back, then made the quickest bowler, industrious but slender Dushmantha Chameera, battle into it early on was a puzzle.

The plot lines are clear for tomorrow.

Sri Lanka will find out how long they'll need to bat to save the test. They should be able to make life awkward for New Zealand if they can get through the new ball.

The home side will do their calculations and prepare to settle in for an afternoon - then whatever they need of Monday - of putting the squeeze on Sri Lanka.

If Sri Lanka focus their minds solely on defence, this is a pitch where obstinacy can be a virtue. The University Oval doesn't crack up, as the West Indies demonstrated in the last test here two summers ago, meaning New Zealand's bowlers may need a decent shovel to dig out 10 wickets.

- By David Leggat in Dunedin

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