Their progress has been built on local products, as Birkenhead can't afford to splash the cash on players other Auckland winter clubs do. They have retained a core of players over the past few years, and others have returned after time away overseas.
Central defender Tom Davis, recently returned from an American college scholarship, has been superb at the back and Jack Salter is another Birkenhead United original who has spent time in the West Australian State League.
"We have a good environment and they seem happy to come back," said Hobson. "We have a lot of players of a similar age [22-25] who know each other and enjoy playing together."
Hobson says the other key has been fitness, with an extra emphasis on conditioning since pre-season.
"We've worked hard all season and have been able to run over the top of teams in the second half," said Hobson.
Their run has sparked football fever at Shepherds Park, with more than 2000 in attendance to see Birkenhead's semifinal victory over Mirimar Rangers last month.
They will be favourites today but are wary of Waitakere, who were unbeaten in the Northern League first division this year and have upset Glenfield Rovers, Caversham and Three Kings on their Cup run.
"They have had a brilliant season and are playing with no fear," said Hobson. "But we'll concentrate on our own game."
The final at 3pm is preceded by the women's knockout cup final between Glenfield and Forrest Hill Milford at midday. Glenfield are looking to complete a hat-trick of wins, while Forrest Hill have yet to lift the trophy.