Rainger is one of six finalists in the Specsavers' Favourite Cricket Umpire national competition.
As a finalist he receives two pairs of spectacles from the sponsors, a cricket bat signed by Black Caps BJ Watling, Kane Williamson and Martin Guptill as well as a double pass to an international game.
No doubt, Rainger is banking on a grand final prize that includes a one-on-one training session with a high-profile national umpire, $1000, two international game tickets, travel, accommodation to the Black Caps v India test starting on Thursday next week at Eden Park in Auckland, and four Black Caps players to visit Havelock North Cricket Club where son Ted, 12, is a member.
Rainger, who has co-coached the Havelock North Year 8 cricket side in the Super League competition with ex-Black Caps coach/batsman Mark Greatbatch, whose son also is in the team, plays down his chances of winning the big one though.
Ironically, Rainger entered the competition on the sponsor's website after "a painful three weeks" of vision following the Year 8 team's victory in the final over Napier Boys' High School at Petane Domain before Christmas.
"I take my umpiring seriously because you have to be fair and accurate," he says, expecting to probably co-coach the Havelock North High colts XI this year.
He went through a coaching course with Hawke's Bay Cricket Association pair of Dale Smidt and Nigel Brooks.
With son taking up Milo cricket several years ago, Rainger, a former Kings College (Auckland) pupil, assumed the mantle of coach by default.
"I do love the contact with the boys and we're lucky to have a couple of representative cricketers in our team," he says, revealing Greatbatch attended the rival Auckland Grammar School.
He affirms umpiring is "the best seat in the house" to watch the game but also carries an added sense of responsibility.
"You've got to be correct and have no bias," Rainger says, adding experience boosts confidence which improves decision making.
The youngsters look up to umpires who in many ways set the tone of a match.
On the field as coach and umpire, he ensures children adhere to etiquette and isn't shy to pull them aside after a game to highlight issues they are unable to address at the height of the match.
His father, William Rainger, of Auckland, loves tennis while brother, Ant, who is in marketing and advertising, has a wicket in the front lawn of his Parnell home.
Before he went to work in Japan in marketing as a 23-year-old, James Rainger went to every single domestic and international cricket match played at Eden Park from the age of 7.
"My love of cricket started with my father. I immerse myself in cricket literature."
He even delved into sports commentating after winning a Classic Hits radio competition to provide Olympics commentary.
He's also had a go at ground commentating at two Black Caps' matches and the former Shell Cup domestic final at Eden Park.
"But that's not really where I wanted to be," says the man who often phones into Radio Sport to share his opinion on sports.
