I followed the odds for the 2020 election. At the end of 2019 Trump was around 8/13. By the summer of 2020 9/2 only coming in to 9/4 by October.
The betting world is a market just like stocks or commodities. It is regulated by market forces. If 10,000,000 people bet $10 on X and only 1,000,000 bets $10 on Y. Then the odds on X is 1/10 against 10/1 on Y. The great fallacy that many gamblers fall into is to think they are betting against the house, they are not. If you make a bet on a horse race, the bookie will make their money regardless of who wins. Odds are shaved to give the house a percentage no matter the outcome. So in reality you are not competing against the bookie, you are competing against everyone else who bets on that race.

@273kelvin I could say more about the morals of betting and the business model, but I will concentrate on my speciality. The Odds System is an unreliable measure ofANYTHING always biased in favour of the "HOUSE" i.e the privileged .

@Mcflewster I would probably agree with most of your moral sentiments about betting. However, the internet has changed betting the same as it has so many other things. In the old days, the bookie chalked up his prices based mainly on the weight of money for each outcome but was sometimes influenced by inside information. Nowadays, any punter (outside of the US) can bet the exact odds down to 4 decimal places, on any event happening or not happening, depending on the amount of money bet on each outcome. The "bookie" is just an internet server that facilitates that transaction, much like the stock or commodities market. It takes a very small % as a fee (0.1% if memory serves). So for example, if you have an either-or event like Biden wins or loses and the betting opinion was completely even? For a $10 winning bet, you would get back $19,98. $10 stake - 1c betting fee. = $9.99 + $9.99 won. The machine has no bias, either way, it simply determines the odds based on money pro/con.
Now if you are wondering how they make money on such small percentages? That is 0.1% on every transaction. Eg. let us suppose you are a shrewd political gambler? In 2018 Biden's odds were 33/1 so you bet $10 on him to win. Now by the end of 2019, his odds have shortened to 4/1 so you decide to hedge your bets and place $200 on him to lose. Now as it stands you will win $330 -$200 = $130 or $50 - $10 = $40. So at the very least, you're $40 up. The system will allow you to take that $40 equity immediately without waiting for the outcome. Meanwhile, it has taken 0.1% of your initial $10 + the $330 + your $200 + $50. So that is 1c + 33c + 20c + 5c = 49c. Still not a lot but multiply that by the hundreds of thousands and it works out as a large sum with no inside information or bias required.

I hope I have explained this without too much complication.

@273kelvin I have never said there was no place for betting. I would like people to nominate the odds but giving reasons for their judgement so we could share their knowledge. The Bookies job would be to decide their reward only if they were right.

The only use of it in sport would be if you could lay a bet on your own abilities to win . This would ensure they get a reward for winning, being paid a portion of the money's wagered and another portion to the organiser of the race and a small amount to the bookie.

Winnings are sometimes made on true facts , not rumours

@Mcflewster It is a mathematical phenomenon that the collective is far more likely to be accurate than the individual, no matter how expert. eg. They did an experiment where several experts were asked to guess the weight of cattle. Then they asked the crowd to submit their guesses. The average guess of the crowd was far closer to the correct answer.

Some bookies did not pay out on the 2020 election until Jan 6th 2021