McCullum's decision not to go ballistic was a key indicator, as was Williamson working through early nerves to make his half-century.
They lost their way a bit when Corey Anderson and Grant Elliott were at the wicket without scoring but they contributed, especially Anderson, who was exceptional in his World Cup debut with 75 off 46.
The team sustained the form we've become used to. Every time they dropped a game or played badly in the warm-ups you thought 'oh no, the bubble's burst, it's all over' but it's more than a bubble now, it's something of substance, like a sturdy plastic water bottle.
This match was where we discovered what they were capable of. The way they built their innings was brilliant. The bowling also came under pressure early but the plans were spot on, like when Trent Boult bowled the yorker with success to dismiss the in-form Lahiru Thirimanne.
Dan Vettori played his part too. He probably gets used at the optimal or easiest times but he does his job. He's so handy to bring on if you make a break-through. Teams lose their momentum and suddenly six more overs have gone and they've struggled for traction. That's a strength.
In whole, you've got several senior players who have taken the attitude 'bugger it, this is our time to be great'. We've heard that a lot over the years that they're world-class players but they weren't producing world-class performances. Now you've got a mentality that we can walk toe to toe with the big boys, look them in the eye, and back it up with performance. They've realised a champion cricket team is only made through consistency of performance.
Often this occurs when young guys like Kane Williamson or Adam Milne come into a team. They can be the catalyst because older guys pull their socks up and say 'I can contribute too'. The situation feeds itself. For instance, they might have gone with Kyle Mills as a steady hand but Milne showed the value in having someone quick. Later in the tournament he could be valuable mopping up a tail bowling at 150km/h.
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