I'm starting to doubt my understanding of English

I hope this is just a misunderstanding of horse racing (I am not familiar with this topic at all). I understand 1 and 2, as for 3, this is a description of how the odds on horses change depending on the results? Well, like if a boxer loses his first fight to an underdog, then his odds for the next fight change and he himself can become an underdog. Right?
Yes, but they change even if it's not the same boxer

So you have two horses with the same pedigree, same trainer, same jockey, same odds, in two consecutive races, if the first
onehorse is a flop
and a total failure, the second one will jump in odds a ton.
Now if you want to hear
soemthignsomethign funny, there was a race in which the fences were damaged in the previous race, the sun was at a bad angle so instead of 12 or 14 fences they had to jump only 2, the rest would be
bypassbypaseds, a horse that was 4x to 5x in the morning became favorite because he was speedy but he was bad at jumping, and, yeah, it won!!!! despite nearly falling at one of the only two fences he had to jump

House edge ensures your loss in the long term.
House edge is the least of my concerns, this is how betting volatility looks 15 minutes before a race
https://www.sportinglife.com/racing/racecards/2025-07-09/fairyhouse/live-show/867123/irish-stallion-farms-ebf-c-and-g-maidenCharles Fort
7/4, 13/8, 6/4, 11/8, 5/4, 6/5 5/4
From 2.75 to 2.25, more than any house edge can take!
I wouldn't really have the patience to place so many bets just to see if this version of Martingale would work or not, but I must admit that I am genuinely curious about the final result..
I'm running out of patience myself because things like this happen:
I was planning on betting $1 on the favorite for the experiments and my own bet for my personal enjoyment $20 for a 123 placing on another horse, you can guess what happened:
