But a much easier argument against sports betting is that it ruins the sports. Players throw. They get good at subtly cheating. The gambling apparatus latches itself to the sport, to the teams and players, the umpires and judges, the sporting organizations. With this much money on the line, it's not a matter of if but when games are thrown, cheated -- the bigger the game, the bigger the incentive. It's even easier now because of the amount of side/parlay betting that is available. It exhausts the spirit of competition.
Sports gambling is diametrically opposed to sport itself.
It ruins lives, funnels money to terrible people, makes sports worse for everyone, and has no positive impact on society. The benefits of the "freedom" to let manipulation of your lizard brain drain you of your past and future earnings is not worth it.
But if you really think about it, yes there might be a tiny portion that wins overall, but they only win because there are a lot of people emotionally invested that ruin their lives. So yes, please ban.
Edit: While yes, it can be fun and I personally can have a lot of fun when I put 50 bucks into a slot machine once or twice a year, no matter the outcome, it doesn't really justify to keep that business alive
Probably explained by chance.
Gambling "systems" don't work unless there's a flaw in the game.
Winning sports betting players often go on to set odds.
As a professional bettor, you're not really outsmarting the sportsbook—you’re trying to outsmart the public. The key is finding moments where the crowd is wrong enough that betting the other side makes sense, even with the sportsbook’s fees. That means you’ll often skip betting when the odds are pretty accurate.
Most sportsbooks will limit how much you can bet if you're too successful, but they usually won’t ban you outright.
The Hong Kong horse race track was a famous example of market-priced bets where the book was run the way you said and the crowd was exploitable in the way you are suggesting. It was one of the last books to work that way.
Sportsbooks will open lines intelligently, but they absolutely do move the line in response to market forces in an attempt to balance money on both sides, because when the money is balanced, they are guaranteed profit.
It's true that when you make a sports wager, the house is paying you out of their wallet. It's also true that they employ a lot of energy and expertise in order to open the betting at accurate odds. However, no corporate, end user facing sportsbook is themselves fading action on one side of the match intentionally. They aggressively try to balance money on both sides so they can guarantee a profit.