Ross Taylor was the second-best batsman in the world between World Cups 2015 and 2019. Martin Guptill averaged 50.01 through the same period; Tom Latham a none-too-shabby 37.86. Where have they been this tournament? Nowhere near their best.

Kane Williamson has, of course, done his best to fill the void, hitting a whopping 30.28% of his team's runs - a higher proportion than even Rohit Sharma, who has made five centuries. But the extent to which his senior top-order teammates have underperformed is staggering. None of Taylor, Guptill or Latham has produced even 60% of the runs they would generally do, through the World Cup. Williamson, meanwhile, has averaged twice his usual amount, to compensate.

Ahead of a semi-final meeting with arguably the most dynamic bowling attack in the World Cup, these are the numbers the three misfiring senior batsmen must address immediately.

Part of Taylor, Guptill and Latham's relative slumps may perhaps be explained by the tougher pitches New Zealand have had to play on during the tournament. In their three tight wins against Bangladesh, South Africa and West Indies, only the match against West Indies saw the teams surpass 250. Ahead of the semi-final against India, Williamson himself suggested this may have something to do with his teammates' relatively modest returns.

"What we didn't quite expect coming into the tournament, was the large variety of conditions that we faced," Williamson said. "That definitely made batting with any rhythm a real challenge for everybody, so being able to adapt with the bat and just trying to contribute to what would be a competitive total is certainly what the most important thing is.

"And the guys' mindsets will definitely be that going into tomorrow's match. We'll have to assess conditions again. But a lot of surfaces in our round-robin play were conducive to only 230 or 240."

Although it is true New Zealand have played on tougher tracks during this tournament, the wickets have not been so tough as to cause a decline of this magnitude. The mean batting average for the matches featuring New Zealand between the last two World Cups was 29.96, while the mean batting average in their matches this tournament is 26.50 - a dip of only 11%. Meanwhile, the combined output of Taylor, Guptill and Latham at this World Cup has nosedived by over 51%.

Taylor's usual consistency has been missed, of course, but he has at least produced two excellent innings in the tournament, against Bangladesh and West Indies. The bigger concern, however, has been Martin Guptill's run of modest form. Following the 73 not out against Sri Lanka in a small chase, in their tournament opener, Guptill's highest score is his 35 against South Africa - that innings cut short by an unfortunate hit-wicket dismissal.

If New Zealand are to challenge India, however, it would appear that runs from Guptill are especially crucial. Although New Zealand have had longer-term issues with their second opener, Guptill's generally good form in between the last two World Cups has largely allowed New Zealand to build a platform before the likes of Taylor come in and build happily upon those starts. There is a sense here that Guptill is the key piece of New Zealand's batting puzzle, and the numbers bear that out. Since the end of the 2015 World Cup, New Zealand make a total of 299 on average, when Guptill makes at least 50. When he falls for less than 30, the average total plummets to 244.

New Zealand have scraped to the semi-finals - their sixth appearance in the final four in the last eight World Cups - thanks in part to the rain. Their campaign has been propped up by their captain, some good performances from Jimmy Neesham, as well as their star bowlers in Trent Boult and Lockie Ferguson. However, if they are to overcome an outstanding Indian side, it is likely they will need a much stronger showing from their experienced top-order hands. Runs from Taylor, Latham and Guptill in particular, may see New Zealand put up the kind of total they have typically made in between the World Cups, rather than their more modest offerings in England.