KOLKATA: New Zealand's impressive bowling and fielding in their unbeaten run at the World Twenty20 has captured the attention, yet batting coach Craig McMillan has been most impressed with his side's adaptability when building totals.

Having won all four tosses, New Zealand captain Kane Williamson has chosen to bat first in each of their games on surfaces that have all differed in pace, bounce and turn.

Their bowlers have then exploited the slow, turning wickets to ensure they won their pool and advanced to a semi-final against either England or West Indies in New Delhi on Wednesday.

"That has been one of the strengths of the guys. They have adjusted really quickly," McMillan said of the batters.

"It hasn't been the wham, bam ...sort of way that T20 cricket has been.

"They have had to assess it ... and have done a really good job of putting the runs on the board to give the bowlers something to work with."

That approach was none more evident than Colin Munro's innings on Saturday against Bangladesh.

The burly left-hander has a career strike rate in excess of 145 in the shortest form of the game, but tempered his stroke making on the slow Eden Gardens' pitch.

Munro scored 35 from 33 balls but hit only two sixes and one boundary along with 17 singles in his innings, with his scoring shots mostly concentrated between mid-on and mid-wicket.

Williamson's man-of-the-match 42 from 32 balls was also restrained though his characteristic cover-drives brought four of his five boundaries as New Zealand scored 145-8 in their 20 overs.

Their bowlers, like they had against India in their opening game at Nagpur, then mixed their pace and strangled Bangladesh's run chase, eventually dismissing them for 70 in the 16th over.

McMillan said he felt the score had been crucial in enabling the bowlers to put pressure on Bangladesh, something that had been evident throughout the tournament.

"I thought the total we got was just above par," McMillan said. "That has been one of the strengths throughout the tournament, we have faced different conditions and managed to get a total just above par every time."