Pakistan's cricket team practice ahead of their second Test match with Sri Lanka at the National Stadium, Karachi, Pakistan on December 17, 2019. Photo: Reuters

Dom Sibley made his maiden Test century for England in the second Test against South Africa, but he had already scooped his family a record ￡21,600 ($28,500) thanks to his late grandfather Kenneth MacKenzie's faith in his talent.

MacKenzie died in 2011 four months after placing two bets on his then-teenage grandson - first at 150/1 then at 66/1 - that he would one day play for his country.

That talent-spotting bore fruit when the 24-year-old opening batsman made his Test debut against New Zealand in November last year. 

His family had no idea they could benefit from a posthumous payout until MacKenzie's daughter Christine Sibley, Dom's mother, went to a William Hill betting shop in Surrey in the southeast of England.

"He'd have been so proud of Dom's achievement, so watching him was tinged with sadness, but he'd also have been delighted at pulling off the bet at massive odds," she told The Times.

Although Mackenzie spotted something special in his grandson when he was just five, he bided his time till he was 16 before placing the first bet.

"It was unreal that Dom's grampi saw the potential and invested in the bet - he was very, very keen and passionate about cricket," said Christine.

William Hill spokesman Rupert Adams said it was a remarkable bit of talent-spotting.