I don't disagree with you, but there is also a heavy element of luck. Lance was astounding in that regard. I'm not a statistician, and I merely got an A- in statistics many years ago now, so smarter, more informed people can correct me, but here is my very simplified mathematical take on this, obviously built on some assumptions.
Let's assume the chance of an event disrupting prep before a GT is 10%, which seems way too low given that Remco and Vingegaard are disrupted for the Tour, Roglic was last year for the Giro, and Pogacar was last year for the Tour.
Then let's say, again conservatively, that the odds of a quest-ending mishap in a GT is 20%. Again, starting in 2023 and ignoring non-Big 4 riders, we had Remco get Covid in the Giro, Roglic crash hard and nearly lose the Giro as a result, and that was better than average, I would say, looking back at Roglic, Froome, Dumoulin, Contador, etc.
So then you get probability that a rider has a mishap before the Giro or during the Giro or before the Tour or during the Tour = probability that a rider has a mishap before the Giro + probability that a rider has a mishap during the Giro probability that a rider has a mishap before the Tour probability that a rider has a mishap during the Tour - the probability that a rider has a mishap before the Giro, during the Giro, before the Tour, and during the Tour = 10% + 20% + 10% + 20% - (10% x 20% x 10% x 20%) =
~59% chance that a rider has a disruptive mishap, even setting aside their relative strength to the competition.
The flaws in my assessment are:
- A good rider like Pogacar might have lower chances of a mishap than someone like Roglic
- My inputs (20%, 10%) are open to debate
- There's a chance my math is completely wrong because, again, I haven't done this in years