Although the book uses the famous 1995 Rugby World Cup Final as a frame to hang the narrative around, it really isn't about the rugby per se. What the real meat of the book concerns is how Mandela made himself a focal point around which apartheid could be pulled down while avoiding the carnage of a civil war. The tense backroom deals and influencing required with the apartheid regime and indeed his own party and friends, are brilliantly described.
The book is excellent in describing the factions and tensions involved at the beginning of the end of apartheid. Transitioning apartheid to democracy could have gone very violently wrong not because of "black vs white" issues as you may simplistically think, but due to the fact there were miriad competing factions on all sides that led to huge danger of mass violence. Mandela's biggest problem at times was convincing the ANC to buy into symbols like the rugby springbok as a way of winning people over as he realised outright rejection of all aspects of the "white culture" would push more of the heavily armed white minority over to the side of the hardliners who actively wanted conflict. When you think how the black majority suffered under the cruelty of apartheid, taking the ANC with him on a conciliatory route was an incredible feat of diplomacy and leadership.
Mandela's genius was to understand the differences between white South Africans in terms of modernisers vs conservatives vs white supremacists, between forward thinking politicians and hardliners in the security services and especially, underlying all, between the English and Afrikaan speakers. He never made the mistake of alienating people by false stereotyping. In prison Mandela taught himself Africaans and deliberately took an interest in rugby as a way of winning over some of his guards, many of who became close friends during his captivity and after his release.
Much detail is included on the Springbok captain, Francois Pienaar, who eventually fell completely under Mandela's spell and captained The Rainbow Nation to rugby glory. In the book Pienaar provides the most striking example of how Mandela could inspire fervent changes in attitudes even in people you'd not expect to be open to his influence. Pienaar was an unlikely convert to Mandela's ideals and as a young man had no political view on apartheid at all - in fact was proudest, as an Africaner, of never losing a school rugby match to "an English school". Mandela handing the Rugby World Cup to Pienaar, both wearing the springbok number 6 shirt, became the ultimate symbol of the real potential for a truely united South Africa against the odds, this book describes how that image became possible.