Black Caps need to keep up their momentum as they tackle the last of their pool rivals in Kolkata today.

Momentum matters in sport; have it and all sorts of possibilities open up.

Take New Zealand at the world T20 championships.

They have played and won their first three group games. Their fourth - with the prospect of a US$50,000 ($74,739) bonus for winning four from four - is against Bangladesh in Kolkata today.

By chance New Zealand are chasing their fourth T20 win over Bangladesh from as many clashes.

Advertisement

The same Bangladesh who completely butchered what should have been a morale-boosting win over hosts India in Bangalore on Thursday.

The same Bangladesh who have had two of their best bowlers rubbed out of the tournament for illegal bowling actions.

Bangladesh are out of contention for the semifinals - and that's precisely why New Zealand will want to be on guard at Eden Gardens.

This tournament of 20-over contests is tailormade for momentum.

It is also, as New Zealand's captain Kane Williamson is fond of saying, a fickle game. One innings, one bowling spell, one bad five-over period can decide a match.

Overs eight to 12 that New Zealand bowled to Pakistan in Mohali on Wednesday morning, conceding just 20 runs when the Pakistanis were flying along, were, in their own way, every bit as significant to the 22-run win as Martin Guptill's man of the match-winning 80 earlier in the night.

"We'll take the same approach as any other game," fast bowler Adam Milne said.

"If we can pick up another win, go four from four, it gives us confidence going into the semifinals on a high."

Milne said the New Zealand players have stuck with the same philosophy which has served them well in the past couple of years: Don't get too high or low, maintain an even-handed attitude.

"We've stayed relatively calm and looked to play our brand of cricket. Sometimes it's a bit risky but it's also rewarding at the moment," he said.

New Zealand have beaten two far better teams than Bangladesh already, in India and Australia.

Bangladesh, shattered by their inability to score two runs against India off the final three balls with four wickets standing, threw away their slim hopes of making the semifinals.

But they do have decent players. Allrounder Shakib al Hasan, his country's finest player, is ranked the world's best ODI allrounder, and second best in the test and T20 categories.

Tamim Iqbal is a dasher at the top of the order; there are young thrusters coming through in the batting ranks and Mushfiqur Rahim is a doughty and talented wicketkeeper-batsmen.

So they lost the plot in Bangalore, but New Zealand should be wary.

They will make the semifinals, but better by far to get there with stocks high than off a loss.

This will be the third game at Kolkata. Batting was not particularly onerous in the first two - Pakistan rattling up 201 against the Bangladeshis; the less gifted Afghanistan getting to 153 for seven against Sri Lanka. But the third, reduced to 18 overs, was a slog, Pakistan making 118 for five and being run down comfortably by India.

No real reason, then, to think New Zealand will stray from their tactical approach, taking pace off the ball, relying on two in-form spinners in Mitchell Santner and Ish Sodhi, who have been as good as any in the tournament.

A place for their leading fast-medium men, Tim Southee and Trent Boult, seems slim. It's horses for courses and if it was a horse race, it would make no sense to have the quickest available not running. But it's not and unless Williamson and coach Mike Hesson see something to raise an eyebrow in the pitch, expect the selection status quo to prevail.