"It's as deep as it's ever been, which is good for the sport."
Walsh is looking to a quirky trend in the history books to help him topple Ryan Crouser.
The Olympic champion has dominated the entire season, sailing past Walsh and others, meet after meet after meet.
But the Kiwi says Americans have a habit of peaking too early before big events, due to their selection criteria.
"To get to the world champs or Olympic Games, they have to get top three in their trials. It doesn't matter if they've already reached the qualifying standard or thrown the furthest in the world, if you get fourth, you're not coming.
"So they have to peak for that and then this [world championships] is six weeks later. Some of them do struggle, but others are able to maintain their form."
Walsh's incredible improvement over recent years has seen his once-strong rivalry with Jacko Gill slip away.
While New Zealand's top putter is aiming for gold, New Zealand's number two is aiming for a place in the finals in London, hoping to produce a throw of more than 21 metres.
Gill has backed his compatriot to upset Ryan Crouser, which pushed his team captain to address their past.
"When Jacko was doing really well through school, I was very concerned about what he was doing and how far he was throwing, and my progress slowed because of it."
"We've both grown as humans, we're older now, we do chat and stuff like that - it's just maturity. For a time, I saw him as a rival - a pure rival - and nothing else.
"But now, if I can help him in any way, I will, and I believe he knows that and will come to me if he needs any help.
"But he's throwing pretty well this year, so he'll be fine."
Charlie Bristow has travelled to London thanks to Air New Zealand