This time last year Ben Duckett had a legitimate claim to be the best multi-format opener in the world.

The left-hander had just led England to victory in the first Test against India at Headingley with a majestic 149 in a canter to a target of 371.

England had won the first of what they wanted to be a defining period of 10 Tests, and Duckett was at the forefront of their hopes of winning the series against India, then going on to regain the Ashes in Australia.

Duckett would have to wait more than 12 months for his next Test century. In that time, England fell apart and the 31-year-old's career was almost derailed.

An Ashes average of 20 formed part of a run of 14 Test innings without a half-century.

The nadir of Duckett's trip to Australia was the footage that appeared online of him apparently drunk in Noosa, not knowing how to get to the team hotel and being asked if he needed an "Uber to the nets, bro".

He was then benched for England's run to the T20 World Cup semi-finals in the spring.

As the home summer began and an England reset got under way, Duckett's Test place was probably not in danger - he had more credit in the bank than opening partner Zak Crawley, who did carry the can.

Duckett wanted to make sure. He pulled out of a stint with Delhi Capitals in what would have been his first taste of the Indian Premier League, probably ensuring he will never get to experience the world's biggest franchise tournament.

Instead, he returned to county cricket with Nottinghamshire to make professionalism his priority.

On a sweltering Friday back at his home ground, Duckett reaped the rewards with a swashbuckling century to keep England in their deciding third Test against New Zealand.

"It wasn't loads of work on my game, I've tweaked a few things here and there, but I've certainly been doing a lot of fitness work since I got back from the winter," he said.

Maintaining - or not maintaining - his fitness has been a recurring theme in Duckett's career. As a youngster, he twice missed out on tours for failing to meet conditioning standards - once with England Under-19s in 2013, then a Northants pre-season trip in 2015.

This time, with a Test career on the line, he has worked with England fitness coach Pete Sim and Nottinghamshire counterpart Zac Bess to lose "five or six" kilograms.

Duckett added: "I started running, which was good!

"I had a four-week block when I got back from the winter where I didn't necessarily hit many balls.

"It's just really important now that I use that hard work that I've done and maintain it.

"It's something I've really enjoyed and it's been great for my mental space and getting away from the game. I went to the gym, I ran a lot and a bit of weight came off."

The early signs for Duckett were good. Three half-centuries in his first five innings for Notts this summer were followed by an unbeaten double century against Surrey.

He still needed the international worm to turn. In the context of the snakepit pitch, scores of 19 and 33 in England's first-Test win over New Zealand at Lord's were useful, only to be followed by more misfortune in the loss at The Oval.

On the second morning, Duckett dropped a simple and crucial catch off Kyle Jamieson as England surrendered the momentum. When he came to bat, he was in glorious touch for 36 before being run out by a never-there call from new opening partner Emilio Gay.

At Trent Bridge, it could have been a similar story. In perfect batting conditions and with England replying to New Zealand's 438, Duckett made his intentions known with two driven fours off Nathan Smith's first over of the innings.

Smith, though, would return to find Duckett's edge. Henry Nicholls should have pouched a simple catch at third slip. When the ball dropped to the turf, Duckett responded by punching the next delivery for four and did not look back.

"I was chatting to [England fielding coach] Sarah Taylor," said Duckett. "We were making a bit of a joke about how I've got to get some luck eventually and that's how the game works.

"I'm extremely thankful for Henry Nicholls for doing that to me.

"It's been a really frustrating time, because I've not felt out of nick, I've just not got the runs that I really want. 'Mother Cricket' was there for me today. I got put down and made them pay for it."

Reprieved, Duckett was irresistible. He peppered the off-side boundary from the seamers and punished the wayward spin of Mitchell Santner with sweeps and whips through the leg side.

With Jacob Bethell in tow, England's second-wicket partnership of 179 rattled along at a run a ball, taking advantage of the pitch, heat and rapid outfield.

When Duckett turned Santner to mid-wicket for the single that took him to three figures, he clenched his fist, screamed in delight, saluting both the dressing room and his home crowd.

"Everyone saw, with how I celebrated, how much it meant to me," he added. "I was actually quite emotional, obviously on my home ground and I haven't been scoring the runs I would have liked.

"After being in the heat for a day and a half to go out there and score a hundred at this ground, it meant the world to me."

Though Duckett was halted on 113 when he chopped on from a Smith delivery, he helped England to a position from where they can complete a remarkable turnaround. They will begin Saturday on 223-2, 215 runs behind.

For England, a winter of discontent has bled into the heat of the summer. Two wins in nine on the field, trouble on adding to trouble off it. Now they have a chance of a much-needed series win that would perhaps inch them away from the trauma of Australia.

But Duckett, who experienced it all with his own low moments, has already moved on and is looking to the future.

"I put the winter to bed when I was playing county cricket for Notts and scoring runs," he revealed.

"I'm not getting any younger, so I want to keep doing this and keep having days like this for as long as I possibly can."