The two F1 teams which have changed the most in 2018

We've almost reached the halfway mark in the 2018 season. The chequered flag on Sunday meant that we've completed 10 out of 21 races, and what a season it's shaping up to be. But which two teams have changed the most inside the past 12 months?

The British team sit at the bottom of the constructors' championship. For many long-term F1 fans, it's a hard sight to see. The team ended 2017 in 5th place scoring 83 points which included a podium before the halfway point. But what has caused such a massive change?

They've lost Felipe Massa, but the problems lie a lot deeper than that. They haven't churned out a good enough car this season. At Silverstone, it was hard to keep on the track. Both drivers had to start from the pits following a change of rear wing in parc ferme.

Sirotkin is yet to finish inside the top 10. While last season the Williams scored in three of the opening four races. It's the definition of the reverse gear.

Going in the opposite direction are Sauber. Bottom of the table last season, they've long outscored this total in 2018 already.

In fact, Leclerc has been involved in two Q3 sessions. Probably unthinkable this time last season. To make matters even more eye-popping, Sauber were pointless after round eight!

What's changed here? The Alfa-Romao deal has given them a little bit more cash. The Ferrari engine is without a doubt stronger. A combination of these two factors has allowed for a major improvement.

The skills of Charles Leclerc also help!