Mercedes team principal Toto Wolff said that you can only assess the performance of two drivers when they compete against each other directly in the same machinery.
Formula 1 fans have long asked the question of who the best driver on the grid is and only rarely are given the opportunity to see the biggest stars paired up as teammates.
In 2021, the superstars will be spread out among the top six teams, with Fernando Alonso returning to the sport to drive for Alpine, Sebastian Vettel moving to Aston Martin and Daniel Ricciardo joining McLaren.
Max Verstappen and Charles Leclerc remain at Red Bull and Ferrari respectively, but Lewis Hamilton is yet to renew his contract with Mercedes after sealing a seventh world title in 2020.
Asked who he felt the best driver on the current grid was, Wolff told Austrian broadcaster ORF that there are many variables involved, making it a difficult question to answer.
“You can only make an assessment like this if you let them compete with each other,” he said. “We’ve never seen Lewis versus Max or George versus Lewis.
“We also do not know the real potential of Charles Leclerc with a top car. There are too many variables involved and therefore it is difficult to answer these kinds of questions with precision.”