Quick guide to the 2015 F1 season so far

Singapore: Quick guide to the 2015 Formula One season so far:

-- Mercedes` Lewis Hamilton is the runaway leader on 252 points after winning seven of the 12 races so far. With seven races left, Hamilton has a lead of 53 points over team-mate Nico Rosberg, meaning he could lift the title without winning again this season.

-- Four-time world champion Sebastian Vettel has convincingly restored his reputation at Ferrari after his triumphant reign at Red Bull ended with a thud in 2014. The German has 178 points to lie third in the standings, 21 points behind Rosberg and snapping at his compatriot`s heels.

-- With Hamilton, Rosberg and Vettel forming an established top three, the most interesting battles are in the chasing pack. Williams` Felipe Massa and Valtteri Bottas sandwich Ferrari`s Kimi Raikkonen at fourth and sixth in the standings, and the Red Bulls of Daniil Kvyat and Daniel Ricciardo have also shown their capability on more than one occasion.

-- Celebrated marque McLaren have disappeared from the reckoning with drivers Fernando Alonso and Jenson Button a distant 15th and 18th on the table -- an unaccustomed position for the two former world champions and one of F1`s most successful teams.