I put $10 on a horse a few years ago, only because I knew her owner.
She came in at 38:1 - I haven't bet since.
What I learned from that was that he was entering her, withdrawing her, entering her again, etc in different races all week, according to who else was entering which other horses.
Like, Duhh...~ of COURSE they are playing the odds (/probabilities) from that side of the table too. Owners, trainers, jockeys all do the math to figure who they want to compete against, this week as well as next season (-:
Though sand bagging per se is almost certainly illegal ...
It affects future race odds as the stats get rolled forwards.
I know about odds vs probability, I still put $5 on powerball maybe once or twice a year.
An almost certain very small loss, a massive potential gain - probability of gain essentially zero, just a pipe dream.
It is loaded in favor of the house, of course it is.
The tragedy is that it attracts those who can least afford it )-;
Not that I can "afford" to throw money around (/away).