Same game, different prices across books. Take the best number every time. Data refreshes every 30 min. Not every book carries every game.
Books price the same market 5-10 cents apart. At -110 you need to win 52.4% to break even. At -105 you only need 51.2%. Over 500 bets a year that's a 5-6% swing in your bottom line - for free.
No events in covered sports at the moment. Check back closer to kickoff.