Bookmakers take bets on more than fifty kinds of sports, from most popular sports: football, tennis - to very rare as: ski jumping, freestyle. Each kind of sport has its own specifics and without knowledge of intricacies of sport, a possibility decreases for win money in bookmaker.
Ten years ago at bookmaker I saw a very funny situation, I watched on TV snooker. I don't remember already who were playing, but it's not so important, let's be called simply the player X vs player Y. Bookmakers take live bets on that game. One bettor named Bob, absolutely didn't understand snooker, he decided to get easy money and placed bet $20 for X player victory in frame, because for player X was a low wager price of 1.3. But just a couple of minutes the player X had made a mistake and passed a cue to player Y. Odds immediately changed on the contrary, for victory player X had become a high 4.0, and for victory player Y became a low 1.3. Bob without any hesitation placed bet $100 on player Y victory, to compensate the loss on first bet Player X and get at least a small profit. Really funny, it's literally a minute later, the player Y makes a mistake and odds reversed again. Bob again puts $300 for player X victory in order to win back bet for Y player victory in frame.
As a result, player Y won frame and Bob lost $290. As it turned out, he didn't understand the rules of snooker game, didn't know the players and that is very important how and why odds were changed.
It was very funny looking for that situation, but it was reason of not understanding the snooker sport.
Before betting on any sport, what you don't know nothing about. Watch it a few times, study rules and only then you can safely place bets and win money.
The eighth bettors error in sports betting: place bet on sport what you don't know.