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Williamson has arrived in Perth as New Zealand's most important player for the Trans-Tasman series, starting on Thursday.
Williamson doesn't get the headlines that Virat Kohli does in cricket-mad India or Smith attracts in Australia, but he comfortably sits aside them as the world's best.
The right-hander has averaged 59 or above in five of his past six years in test cricket. His overall average of 52.68 is the highest of any Black Cap in history.
"He plays the ball incredibly late. He is patient," Smith said.
"I like that in test cricket, personally. It just helps playing the ball a bit later and I think he plays it a bit later than anybody else in the world.
"Terrific work ethic and a good eye and plenty of time. I think he has loads of time against quick bowling.
"He is a quality player and hopefully we can keep him quiet this series."
Williamson has also performed on Australian shores before, with centuries in the first two tests of the 2015-16 tour.
But the Black Caps are not a one-man band with the bat.
Ross Taylor needs just 151 runs in the series to go past Stephen Fleming as New Zealand's all-time leading run-scorer.
He hit 290 on his last visit to Perth for a test.
Brian Watling also hit a double-hundred just last month against England, while Tom Latham and Henry Nicholls also both average above 40.
"We're very fortunate we have a top five that have been scoring a lot of runs of late," New Zealand quick Tim Southee said.
"And different guys have been standing up a different times over the past few years.
"Not only having Kane and Ross there, but the likes of Tom Latham and Henry Nicholls, who has done a great job for us over the past few years as well.
"And then you've got someone like BJ Watling who loves a scrap and tough situation to come out as your keeper-batsman to come out as well."