Firstly since Pogacar and Vingegaard are so evenly matched on climbs we really need to be looking at
Kus v Majka ...that is the real battle here
Which of these guys can help determine the race ? Because it may come down to that
I am not sure where you learned probability but your estimation makes no sense
Sure G has been behind Pog and Vinge on the climbs but its the third week of a very hard Tour where stamina will count plus there is the TT and at the tour anything can happen...Id say the probability is much higher.If we say Vinge and Pog were twice as likely to win than Thomas then that still give Geraint a one in 5 chance but its probably nearer to 10% to 15% as Pog/Vinge are 3 times more likely to win at this point than Thomas but that probability is not fixed and can change every day
The only reason for why Geraint still has a chance in this TDF is Pogacar and Vingegaard being too busy with each other and giving him 0 attention throughout this Tour. Reality is that they can drop him on a climb way too easily and given the nature of the climbs in the Pyrennes he will most probably end up before the ITT with around 5 minutes to recover so yeah, I believe he's got 0.001% to win it unless both Vingegaard or Pogi retire from the race.