10. Brendon Hartley, Toro Rosso – 13.79 percent of teammate's points

Pierre Gasly: 29 points
Brendon Hartley: 4 points

It was a tough year for Brendon Hartley at Toro Rosso, capped off one day after the season ended when the team confirmed it would be replacing him with Alexander Albon for 2019.

Hartley certainly endured a lot of bad luck, such as in Canada when he made a good start before a big accident with Lance Stroll, but ultimately ended the year with just three top-10 finishes and a final total of just four points.

By comparison, teammate Pierre Gasly racked up 29 points, highlighted by a fourth-place finish in Bahrain. That result alone tripled Hartley’s score for the entire season.

It leaves Hartley as – statistically – the weakest teammate in F1 this year, scoring only 13.79 percent of Gasly’s points.