Mercedes technical director James Allison believes reliability will be the key factor in deciding which way the F1 title race swings over the second half of the season.

Kimi Antonelli leads the drivers’ championship by 50 points with a scheduled 12 rounds remaining, with Ferrari’s Lewis Hamilton his closest challenger and George Russell a further five points back.

Mercedes, meanwhile, have a 72-point lead in the constructors’ championship over Ferrari as Formula 1 returns this weekend with the final iteration of the Dutch Grand Prix at Zandvoort.

Allison, who leads Mercedes’s power unit programme and has now been at the team for a decade, believes that the potential cost of losing a maximum of 25 points with a mechanical failure is more significant than updates over the remaining weekends.

"Everyone naturally focuses on upgrades because they're visible and they're exciting, but reliability may end up having a much bigger impact on the championship," Allison told Mercedes' Nu Silver Arrows Radio Show.

"A successful upgrade programme might gain you 10, 15 or perhaps 20 points over the course of a season, depending on the circumstances.

"A single retirement can cost you that amount in one afternoon. So while we're committed to continuing development, our biggest focus going into the second half of the season is reducing the self-inflicted wounds that have cost us points in the opening races.”

Russell was forced to retire from the lead in Canada while Antonelli suffered issues in Barcelona and Silverstone.

"We've had reliability issues and operational setbacks that simply shouldn't happen, and addressing those areas is arguably more important than the next upgrade package,” Allison added.

"If we can continue to improve the car while also delivering clean execution and reliability, then we'll put ourselves in the strongest possible position for the championship run-in."

Mercedes have not won a drivers’ title since Lewis Hamilton’s triumph in 2020, while their last teams’ championship came in 2021.