It is an irony lost on no one that in a country with such a prominent history of racial tension, the world will be watching on Thursday as a black woman who grew up in the poor townships of South Africa sits in judgment of a white man of class, privilege, and wealth.

But that's what will happen when Judge Thokozile Matilda Masipa this week reveals her verdicts in the murder trial of Oscar Pistorius.

By now, Judge Masipa will likely have made her decision. She will have decided whether Pistorius murdered his girlfriend by intentionally firing four shots into his bathroom door on Valentine's Day last year, or whether he did so in the mistaken belief he was about to be attacked by a violent intruder.

With the assistance of two assessors, legally trained assistants with whom she has consulted throughout, the evidence and arguments have been carefully weighed, examined and debated on each of the four charges Pistorius faces.

In doing so, it is tempting to imagine the former crime journalist in Johannesburg quietly pinching herself at this situation of this case, which has seen her become internationally renowned – if only as "My Lady", as all in court address her – and at the centre of what has been dubbed the "trial of the century".

Indeed, the bench of the Pretoria High Court is a long way from her two-room childhood home in historic Soweto, outside Johannesburg, where she grew up as the eldest of 10 siblings.

But only she and three others are still alive; five of her siblings died in childhood, another brother stabbed to death in his 20s.

This experience of tragedy is perhaps the only thread of commonality she shares with Pistorius, the man she must judge.

Pistorius had both his legs amputated at the age of just 11 months, having been born without either fibula.

He also lost his beloved mother, Sheila, who died when he was 15; a woman he had credited with encouraging him to achieve things in spite of his disability, and doing everything his able-bodied friends did.

Both deservingly command respect for their achievements.

For many years a crime journalist, Judge Masipa graduated with her law degree in 1990, aged 43, and a few months before Nelson Mandela's release.

Just eight years later, she became only the second black woman appointed to South Africa's High Court. She has reputation as a fair and fearless judicial officer.

Known as "Tilly", Judge Masipa has kept a cool head and displayed quiet authority since the trial began on March 3 this year, under the glare of live television cameras broadcasting her every utterance. She has spoken only when absolutely necessary, with carefully selected words.

If she has been sympathetic to any witness, horrified by the manner of Reeva Steenkamp's death, appalled by lawyer tactics, or frustrated by the pace of the case, it has been imperceptible.

Across the court, Pistorius, the accused, is, of course, an international hero. He is the Blade Runner, so-dubbed for his speed on carbon fibre blades, and his extraordinary achievement in competing alongside able-bodied athletes at the London 2000 Olympics.

But on Thursday, Judge Masipa will once more make the short walk punctuated by a gentle limp that is believed to have been the result of childhood polio, to her seat at the raised bench.

From there, she will look down on Pistorius, and their worlds will once more be galaxies apart.

With the eyes of the world on her, she will judge him.

Lisa Davies will be in South Africa for the verdict. Follow live updates on smh.com.au / theage.com.au