What Hamilton must do to win his sixth F1 title at 2019 Mexican GP

Bottas's victory in Japan last time out trimmed Hamilton's advantage, but the Briton still holds a 64-point lead with just four races left.

Hamilton needs to extend that by 14 points in Mexico to become champion again, as only 78 points will be on offer over the final three events.

However, due to Ferrari's form and Red Bull's recent prowess at the Autodromo Hermanos Rodriguez, Hamilton said he does not "anticipate it will be Mexico" where the championship is decided.

"I think we will be battling for a good few races," he said in Japan. Victory alone will not be enough for Hamilton to win the title this weekend.

Even if he wins and bags a bonus point for fastest lap, Hamilton will need Bottas to finish off the podium to secure an unassailable lead.

But Hamilton can finish as low as third and win the championship if Bottas finishes no higher than 10th.

If Hamilton is not on the podium - which has happened at the previous two Mexican GPs - he will need to wait at least one more weekend even if Bottas fails to score points at all. Hamilton's title permutations

The bonus point complicates matters. If Hamilton fails to set the fastest lap, or Bottas gets the extra point, then Hamilton is champion if:

But if Hamilton sets fastest lap, the permutations shift slightly. He will be champion if:

While Hamilton's sixth title is effectively a matter of time, barring a stunning turn of events, his team boss Toto Wolff said a sixth consecutive championship double for Mercedes is something "no one would have dreamed" would happen.

But he anticipates neither of his drivers having a straightforward grand prix in Mexico.

"We know that the four remaining races are not going to be easy and we expect Mexico to be the most difficult one for us," said Wolff.

"The high altitude of the track brings some fairly unusual challenges as the low air density affects the downforce of the car, the cooling and the engine performance.

"It's a combination that doesn't particularly suit our car, but we will give it everything to try and limit the damage."