South African schools take their rugby so seriously that anyone watching a game could be forgiven for thinking that the match was a matter of life and death.
But if you asked the thousands of boys across the country who charge on to rugby fields week in and week out, they will probably tell you it's more than even that.
This passion has resulted in the publication of Derby Day - South African Schoolboy Rugby, which is a detailed and in-depth, 400-page glossy look at the history and culture of the country's 100 top schools.
It is published by Laugh It Off, the company responsible for satirical T-shirt logos which have resulted in a number of court cases over the years.
Derby Day - South African Schoolboy Rugby investigates some of these schools' traditions and heroes by speaking to school rugby coaches, players who made the schools famous and other old boys.
In KwaZulu-Natal, arguably the biggest games of the school rugby season are Durban High School (DHS) against Maritzburg College, and in Durban particularly it's this year's world school champions Glenwood High School against DHS.
Nine schools from KwaZulu-Natal feature in the book: DHS, Glenwood, Maritzburg College, Northwood, Westville Boys, Kearsney College, St Charles, Michaelhouse and Hilton.
The book goes back to the birth of rugby in these schools and then explains how the sport developed there, to ultimately being one of their defining features.
The book also reveals which schools Springbok and other international rugby players attended.
Glenwood High School has produced Springboks such as Mauritz van den Berg, Roger Sherriff, Don Walton, Rodney Gould and John Allan. Allan also played for Scotland.
DHS has produced Springboks Neville Todd, Andrew Aitken, B J Botha and All Black Greg Rawlinson.
Allistair Hargreaves also captained the DHS first team between 2002 and 2004.
In the book Botha says: "When I was at DHS, we always compared ourselves to the best school. So it was usually a comparison against Maritzburg College as they were consistently the strongest side. Beating College at Goldstones will always be one of my best rugby memories."
College has produced the most Springboks of all KwaZulu-Natal schools. Among these are Bill Payn, Phil Nel, who captained the 1937 Springboks, Joel Stransky, Pieter Dixon, Butch James and Peter Grant.
They have also exported international players to England, Italy, the United States and Zimbabwe.
Another school with an interesting rugby history documented in the book is Kearsney College. The school produced Etienne Fynn and Trevor Halstead. Fynn later played for St Charles College.
According to Kearsney coach Kevin Smith: "Ettienne was a fat little 12-year-old when he arrived at Kearsney in 1984. But I thought he might be a decent rugby player if he gave it a try.
"When he reluctantly arrived at practice I pushed his head into a scrum machine, positioning him so that he could scrum.
"He immediately came up, complaining that he'd rather play soccer."
Other KwaZulu-Natal schools with strong rugby traditions are Michaelhouse and Hilton College, who spawned Springbok rugby players Wayne Fyvie, Hentie Maartens, Gary Teichman and Bob Skinstad.
Laugh It Off founder and co-author Justin Nurse said the book was the brainchild of a teacher friend of his, Mathew Knight, who wanted to do a book on the two things South Africans love most; school and rugby.
Nurse, whose claim to fame has been his spoof T-shirts which have annoyed almost every major brand in South Africa, said this was his first venture into mainstream publishing.
"I have been publishing Laugh It Off annuals but nothing amazingly lucrative," he said.
Nurse and the two other editors, Bryce Hepburn and Ruan Kemp, took school and rugby and combined it in the form of a road trip - they travelled around the country for more than a year, visiting schools to feature in the book.
"FNB gave us some money to get going and I paid some costs."
Nurse said they launched the book on the television programme Boots 'n All on SuperSport almost a year ago.
"It has been very well received. The reaction has been overwhelming because South Africans are proud of their schools and they all love their rugby. We have sold 3 000 copies to schools."
- Derby Day - South African Schoolboy Rugby retails for R300 and is available at most bookstores.