If Leo wins the last round and Tris is second the championship will be:
Leo 334 + 50 - 37 = 347
Tris 333 + 43 - 37 = 339
If Tris wins the last round and Leo is second the championship will be:
Tris 333 + 50 - 37 = 346
Leo 334 + 43 - 37 = 340
There are lots of other permutations but essentially the championship will be decided on which one finishes ahead of the other. No other driver has a chance.
Good luck gents and drive fairly, I wouldn't want the championship to be decided in the stewards room. We don't have a Michael Massey on the moderating staff