How F1 title can be won in Abu Dhabi

As we reach the final grand prix of the season, the Formula One drivers' championship is now down to just four contenders.

1) Fernando Alonso 246

2) Mark Webber 238

3) Sebastian Vettel 231

4) Lewis Hamilton 222

How many points are available in the final race at Abu Dhabi:
From first to 10th: 25-18-15-12-10-8-6-4-2-1

Who could win and how

Webber cannot win championship if P6 or lower.

Vettel cannot win championship if P3 or lower.

Hamilton cannot win championship if P2 or lower.

Alonso v Webber

If: Alonso P1 or P2: Alonso takes the title on points

Alonso P3, P4 or P5: Webber needs to win

Alonso P6, Webber needs P2

Alonso P7 or P8: Webber needs P3

Alonso P9: Webber P4

Alonso P10 or no points: Webber P5

Alonso v Vettel

If: Alonso P1, P2, P3 or P4, beats Vettel on points

Alonso P5, P6, P7, P8 : Vettel needs to win

Alonso P9, P10: Vettel needs P2

Webber v Vettel

If: Vettel P1: Webber cannot win

Vettel P2: Webber P4 or better

Hamilton

Must win, Alonso P11 or worse, Webber P6 or worse, and Vettel P3 or worse.