The Kiwis have elected to bat against Pakistan on Wednesday (Jun 26) after winning the toss which was delayed due to wet outfield at Birmingham.
Kane Williamson's side are undefeated at the tournament in England and Wales, with five wins in six games, plus one no result.
In contrast, Pakistan must win the match at Edgbaston if they are to maintain a realistic chance of reaching the semi-finals after a poor start to the tournament in England and Wales.
Mahmood, a former allrounder who played in three World Cups for Pakistan, said New Zealand had a good record early in tournaments but often wilted under pressure at the business end.
"New Zealand's history is such that they get there winning, winning and then when a crunch situation comes up, in the semi-final, or quarter-final, they don't do that well," Mahmood said on Tuesday.