"A bit of it is hard work, but a large amount is the work the teachers put in," Eben, 18, said.

"It can't be overstated, especially with the new syllabuses [in English, mathematics and science] coming in, they did so much to get us ready for the unknown when there were no past papers.

Related: Hunter's Hamish named the only student outside of Sydney to receive highest possible ATAR

"They had faith in us and they brought us through.

"They've done us well and I think we made them proud as well with the work we put in."

Eben received an ATAR of 99.4, which made him the dux of Merewether High.

The Hunter's only academically selective school had a large group receiving ATARs over or near 99, as well as the region's largest number of students on both the Top Achievers (four accelerated year 11 students) and All-Round Achievers (15) lists.

Related: Newcastle Grammar School has seven students named "All Round Achievers" in the HSC 2019

The title for the region's highest ATAR went to Hunter School of the Performing Arts' Hamish Lewis, with 99.95. Just 46 students across NSW received this ATAR. The median ATAR was 69.75.

St Philip's Christian College Newcastle's Jack Temelkovski achieved 99.55. Newcastle Grammar School's [NGS] Acacia Ozturk scored 99.8, Nicholas McGrath 99.45 and Kavini Palipana 99.25.

Merewether's Eben said he was "relieved" to receive the ATAR needed to study physics at the University of Sydney.

"It provides the tools to be able to understand how the world works," he said.

"It's amazing to look at phenomena and say 'I can understand what has happened here' and predict what will happen in the future."

Related: Hunter students stand out in HSC First in Course ceremony

Eben said doing "a little bit a lot", adequate sleep and taking time away from study to recharge was critical to performing well.

"I found putting in a little bit of work here and there and building up to something was good, rather than doing a big lump sum of work, so it doesn't get daunting," he said.

"It also helps you get a full understanding of the topic rather than a surface level appreciation."

Merewether's dux based on internal assessment, Sophia Scepanovic, received an ATAR of 99.3.

She has already received early entry through the University of Sydney's Future Leaders Scheme into a commerce and advanced studies degree. She is also eligible for a scholarship under the Sydney Scholars Awards.

She said she was motivated to do the absolute best she could.

"I was worried about the subjects I chose because they're known for not scaling very well.

"It's a big deal for me and important for others to know scaling is not everything. I'm really proud showing myself I can do it."

Sharvil Kesarwani, who achieved a silver in the Asian Pacific Mathematics Olympiad this year, received 99.15 after studying 16 units.

This included Mathematics Extension 1 and 2 when he was in year 10, plus biology last year.

"I was more interested in learning than the ATAR," he said.

"I thought if I focused on what I wanted to learn then success would follow."

Still at Merewether, Arthy Mukunthan and Aditya Enjeti both received 99.1 and Teza Sankoorikal got 99.05.

Charankarthi Musuwadi - whose advice was "input equals output" - and Jack Lyons both received 99.

Jai Rose Sabu received 98.95, Eamonn Hanna 98.8, Angus Atkinson 98.75 and Leah Dove 98.45.

St Paul's Catholic College Booragul's Thomas Fairleigh received the Diocese of Maitland Newcastle's highest ATAR with 98.25.

NGS' Julianna Sebastian received 98.8, Lukas Lechner-Scott 98.7, Emily Prickett 98.5, Isla Hutchinson 98.15 and Ryan Turner 98.

Merewether principal Christine Rippon said the school was pleased to see the performance of this year's cohort on par with in previous years, especially considering it was the first group being tested on the new syllabuses.

"The teachers have worked so hard," Ms Rippon said.

"Sometimes we were concerned we were over teaching them to make sure they had everything they needed, but obviously we weren't."

She said students achieved 65 band sixes across four levels of mathematics and 102 band sixes across four sciences: 55 in biology, 20 in chemistry, five in earth and environmental science and 22 in physics.

The school has seen its NSW ranking jump from 59^th last year to 49^th this year.

Ms Rippon said it could move to around 30th if it told students to drop additional subjects that put them above the mandatory 10 units, or subjects that didn't scale well.

"But that's not what it's about," she said.

"They'd be bored to tears.

"They need to be challenged and engaged. These kids have a well rounded education that holds them up as they move on."