Kat can finish seventh in Brazil and leave as D2 champion. That is the luxury Abu Dhabi bought her.
She starts the finale on 175 points, with Walter on 152 and Webbah on 147. A perfect weekend is worth 32: 30 for the win, one for pole and one for fastest lap. P7 pays nine.
Nine points would take Kat to 184. Walter can reach the same total, but only by taking everything, and a tie would still favour Kat on countback: she already has three wins; victory in Brazil would give him two. Webbah cannot reach 184 at all.
The championship therefore has a very clear dividing line. P7 ends it. P8 opens the door.
The D2 title ladder
The routes below assume Kat scores no pole or fastest-lap bonus. Any bonus she earns raises the requirement facing Walter and Webbah.
| Kat finishes | Kat's final total | Walter must… | Webbah must… |
|---|---|---|---|
| P7 | 184 | Cannot win the title | Cannot win the title |
| P8 | 182 | Win with either bonus | Cannot win the title |
| P9 | 180 | Win | Cannot win the title |
| P10 | 178 | Win | Win with pole and fastest lap |
| P11 | 177 | Win | Win with either bonus |
| P12 | 176 | Win, or finish P2 with both bonuses | Win |
| No race points | 175 | Win, or finish P2 with either bonus | Win |
Walter needs the first crack
Walter has the broader set of routes because he is five points closer. At P8 for Kat, a plain victory is not enough; he needs pole or fastest lap with it. At P9, the win alone does the job.
Only when Kat falls to P12 does second place become useful, and even then Walter needs both bonuses. If Kat scores nothing from the classification, P2 with either pole or fastest lap would finally carry him past her.
There is plenty for Walter to control in those equations. He can qualify at the front, chase the fastest lap and put himself in position to take 30 points. The problem sits in the first column. Every route begins with Kat finishing below seventh.
Webbah has a win or nothing
Webbah's side is harsher. Kat finishing ninth eliminates him, regardless of what he does. P10 gives him a route, but only through the full 32-point weekend. At P11, a win and either bonus is enough. From P12 down, victory on its own would complete the comeback.
Pole and fastest lap are hardly alien to him. Webbah has four of each in D2 this season, more than either title rival. Yet even his best possible afternoon cannot repair a merely decent one from Kat.
That is a brutal change from Japan, where Webbah led Kat by 29 points and appeared to have the championship under control. Kat won at Monza while his penalty dropped him to fourth, cutting the gap to 14. She won again in Abu Dhabi when he was absent, moving past Walter as well and taking a 28-point advantage over Webbah into the final round.
Two races have turned Webbah from the driver protecting a lead into the one who cannot afford to finish second.
Kat can race the number
The temptation for Kat will be to treat Brazil like any other race. The mathematics say it is nothing of the sort.
Walter and Webbah need the front of the field, the bonus points and a weak afternoon from the championship leader. Kat needs ninth place to eliminate Webbah, seventh to eliminate everyone, and no interest whatsoever in making the finale more dramatic than it already is.
Brazil's title fight is lopsided by design. Walter and Webbah have to race for everything. Kat can race for seventh.
