Back in 2020, former McLaren team boss Martin Whitmarsh shared the intriguing test based on which he decided to hire Lewis Hamilton in 2007. The Brit shared a hilarious theory, saying he would only hire a driver if he felt he would be unhappy to see his own daughter bring them home.
Other than Ron Dennis, Whitmarsh was the key figure involved in bringing Hamilton to the McLaren F1 team in 2007. Speaking to the BBC in 2020 about how he decided to hire the driver, Whitmarsh shared a hilarious theory.
The Brit explained that while hiring drivers, he would never want to sign a driver that he would be happy to see his daughter bring home. Whitmarsh explained that he would look for a pilot who would actually have the qualities of a bad partner, like selfishness and self-possessiveness.
He then explained how he applied the same theory for Hamilton back in 2007.
"As much as I love Lewis to death, would I be happy for my daughter to bring him home? No. As part of the complex equation of talent, intensity, focus, they also have to have a bit of ruthlessness," said Whitmarsh.
"Lewis had that and he was bloody young. Would he be any different today? Probably not. And that was it, just bloody minded," he added.
McLaren signed both Lewis Hamilton and Fernando Alonso in 2007. Alonso was the reigning world champion and expected to be the team leader against a rookie. But as the season unfolded, Hamilton matched, and sometimes even bettered Alonso's performances, leading to McLaren choosing not to favor one driver over the other.
The internal team battle meant neither driver was able to win the championship in what was the quickest car in 2007. It also led to a rift between Alonso and the McLaren team management, and the driver left after just one year. Hamilton won the world title the subsequent year.
When Martin Whitmarsh recalled the story of Lewis Hamilton leaving McLaren in 2013

Speaking during the aforementioned interview in 2020, Martin Whitmarsh revealed that leaving McLaren was "the most difficult decision" of Lewis Hamilton's life at the time. But the team boss also explained that he felt it was the right move for the driver.
Whitmarsh explained how Hamilton was emotional about leaving the British team at the end of 2012:
"It was the most difficult decision of his life. He was emotional about it. But at the time, I sensed it was the right decision for him, and subsequently it’s proven to be just that."
Whitmarsh also claimed that Hamilton was extremely protected by his father and Ron Dennis when he was at McLaren, and needed to leave the team to grow as a driver and become "his own man".
Leaving the Woking-based team did indeed prove to be the right decision for the driver's career, who claimed six world titles at Mercedes, becoming the most successful driver in F1 history.