Romain Grosjean (Lotus), Grade: A-
Grosjean was certainly the dominant force at Lotus during 2015, thrashing Pastor Maldonado in qualifying and scoring nearly double the points of his Venezuelan team-mate. While the Lotus E23 certainly won't go down in history as Enstone's finest effort, Grosjean did his best with it and managed to bring home enough points to keep his team ahead of Toro Rosso. Although his season didn't bring the top teams a-knocking for 2016, it attracted the attention of the new Haas F1 team. Hopefully, this new beginning leads to good things for a driver who has come a long way since the days of 'Crashjean'.
Pastor Maldonado (Lotus), Grade: D
Maldonado produced a rather hefty number of disappointments in 2015, including being firmly put in his place by Romain Grosjean and generally sticking to an approach to racing that hasn't yielded anything of substance, except for his sole victory back in 2012. There is little else to say about a driver who remains unable to see the error of his ways and who is largely kept in the sport thanks to a hefty briefcase full of cash.
Max Verstappen (Toro Rosso), Grade: A
Formula 1's youngest-ever driver delivered a rookie year to remember and is rightly touted as a future world champion. His maturity, raw speed and race-craft make him a very complete racing driver, even at the tender age of 18, a view corroborated by his brave, no-nonsense, and (most importantly) generally successful overtaking attempts. Verstappen is the Rookie of the Year, and given that all the hyperbole that could be used to describe the youngster has already been used, it is sufficient to simply note that his future is bright. Very bright.
Carlos Sainz (Toro Rosso), Grade: A
Despite not being surrounded by the same hype as his team-mate, Sainz quietly went about his business and can be well-pleased with his first season in Formula 1. He has proven to be a safe bet behind the wheel and is only likely to improve as time passes. He seemed at times to lack the raw edge that Verstappen was able to use to good effect without coating the circuit in carbon fibre, but in fairness, Sainz is being compared to a very high standard and his thorough, deliberate approach to the race weekend should serve him well going forward.
Felipe Nasr (Sauber), Grade: B-
Nasr's first season in Formula 1 started strongly when he bagged a good haul of points at the season-opening Australian Grand Prix. Unfortunately, as the season progressed, Sauber fell behind in the development race, making future top five finishes impossible. While Nasr generally acquitted himself well against team-mate Marcus Ericsson (who started his F1 career last year) the fact that Nasr barely edged the qualifying battle (10-9) is a cause for concern given Ericsson's standing in the F1 paddock. On balance, the young Brazilian merits another chance.
Marcus Ericsson (Sauber), Grade: C-
Despite not setting the world alight at Caterham last season, Ericsson found himself moving up the grid by joining Sauber, before being beaten soundly on race day by his new rookie team-mate. The Swede was certainly more of a match for the Brazilian on Saturdays, but in general, he has hardly set the world alight and has done little so far to deserve a spot at Sauber, which was the home of drivers like Perez and Hülkenberg not too long ago.
Fernando Alonso (McLaren), Grade: B
Alonso endured a torrid year at McLaren and was forced to make do with a car that seemed to prefer being up on the jacks rather than out on circuit. The Spaniard certainly drove well in trying circumstances but seemed at times to lack his usual fighting edge and 'drag the car by the scruff of the neck' approach. To his credit, he was the first to admit this. Of course, there is little a driver (even of Alonso's talent) can do with such a limited car, but there was a little something missing in the two-time champion's driving at times.
Jenson Button (McLaren), Grade: B
Button generally did well given the sheer number of reliability issues he was forced to endure. Furthermore, he scored points when they were on offer and performed admirably against Alonso, who is considered by many to be a tier above him. The Briton was his smooth, reliable self and remains a safe bet behind the wheel, even if he sometimes seems to lack a tenth or two when it matters.
Will Stevens (Manor), Grade: C-
Even with the modest machinery at his disposal taken into consideration, Stevens failed to produce anything that suggests that he should retain his spot on the F1 grid. After the two Manor cars eventually reached parity, Stevens tended to trail team-mate Roberto Merhi both on Saturday and Sunday and had a tough time dealing with Alexander Rossi, who was thrown into the deep end while Stevens had been driving the car all year. While the young Brit remains hopeful of securing a seat for next year, such an outcome seems to depend more on his financial backing rather than on raw talent.
Roberto Merhi (Manor), Grade: C
While Merhi didn't particularly make any of the midfield teams sit up and take notice he did generally have the measure of Will Stevens, especially as the season progressed. Should the youngster fail to secure a drive for next year it is unlikely that any tears will be shed in the F1 paddock, but if their respective performances in 2015 were the only relevant factor, Manor would do well to keep Merhi rather than Stevens.