Ex-England international Josh Lewsey Wednesday said the British and Irish Lions had a great chance to overturn the All Blacks this year with the rebuilding world champions not at the "peak of their powers".
Lewsey, speaking at the official launch of next month's Hong Kong 10s tournament, said the timing was good for Warren Gatland's Lions as they bid for their first series win in New Zealand in 46 years.
He said the All Blacks were "on their own journey" after greats including skipper Richie McCaw and fly-half Dan Carter stepped down following the team's second successive World Cup victory in 2015.
"You can't just replace those (players) overnight, it takes a while," Lewsey said.
"That doesn't mean players coming in aren't just as exceptional, but bonding a team tends to take five, seven, eight years, for a team to really go for it."
He added: "If you are going to go down there and have a result, you're not playing a New Zealand who are right at the peak of their powers, so of course it's an opportunity."
Lewsey, 40, started all three Lions Tests on their last tour of New Zealand in 2005, when the visitors were whitewashed 3-0.
He tipped Lions coach Gatland to impose a cohesive style on this year's composite team drawn from England, Scotland, Ireland and Wales.
"Warren will have a very clear strategy about how he wants to play, and similarly, he will pick players who are most suited to play that style," Lewsey said.
"If you've only got a group of guys for a short period of time, it's the most effective way of gelling, and to be really clear what you want to do."
He added that Gatland, a New Zealander, would know all about the strengths and weaknesses of the All Blacks ahead of the tour, which gets underway in June.
Lewsey joked it would hard for the 2017 team to be less successful than their predecessors 12 years ago under former England coach Clive Woodward.
"Perhaps we could have been more specific in terms of how we wanted to play," he said.
"Because if you look at the teams in '05, man for man we had a fantastic group of guys, and obviously the Test series spoke for itself in terms of scoreline.
"But I can't help but feel with the talent we had, we underachieved."