Visitors to Las Vegas or online sportsbooks may come across some games on the betting board that will have special rules attached in the betting. Such games will be circled on the betting board. A red box means that the line is "circled" and subject to reduced betting limits.
Often time's sportsbooks will circle games on the betting board due to injuries to impact players. NFL teams competing on Sunday's must submit their injury reports on Friday and provide updates on Saturday. In recent years the NFL adopted a rule forcing teams to disclose on Wednesday through Friday who missed practice and who had limited work during practice. The best practice for sports betting professionals would be to browse individual team websites that post the injury and practice information about the health of their players.
The injury reports have been very accurate in recent years because the NFL wants to protect the integrity of the league because inside information on injuries could be exploited. So teams have been very forthcoming about the health of their players. Injuries to impact players like the starting quarterback, running back and impact wide receivers will cause Las Vegas and online sportsbook to circle the game on the sports betting board until their status come game time is determined. Sharp sports bettors follow the best practice of shopping individual sports books to shop for the odds that are best set on the side they want to bet on.
Sometimes Las Vegas or online sportsbooks may miss important injury information on teams and a smart bettor may bet into a good betting number that favors the bettor. Professional gamblers look for knee, foot and ankle injuries to running backs. A running back who is not 100% healthy and playing with ankle, foot or knee injuries will see their average yards per carry often fall well below their average. This puts the offense in second and third and long situations or what is known as obvious passing situations. Defenses who know the pass is coming can adjust into pass coverage creating less space for the wide receivers to run routes making a pass completion by the quarterback much more difficult which raises the possibility of a turnover. With a capable back up running back it is often better for a team to not play a running back that sports ankle, knee or foot injuries. Many professional sports bettors will look to play against a team who is starting an impact running back who is playing with an ankle, foot or knee injury.
If inclement weather is forecasted for the site of an outdoor game a sportsbook will circle the game and bettors will have betting limits reduced on the game up until about an hour until game time. Wind can factor greatly in the passing game and the best practice for professional sports bettors will look to play under in college and pro football if the betting line has not already been bet down. There are times when the professional has the inclement weather information before the Las Vegas or online sportsbook and this is a scenario when they make advantage bets.
Many sports bettors will find NBA games circled on the Las Vegas or online sports betting board. Often times an NBA team will report a mild ailment from a player in their rotation and list them as questionable or doubtful. Smart betting professionals will tune into NBA team's pregame show 30 minutes prior to the start of the game to get specific injury information about teams impact players on their rotation. In the NBA if an impact player is lost to injury the replacement player will often step up and the team will have point spread success in the first game the team plays without their impact player in the lineup.
A line may be circled when factors other than game play (e.g., injuries or weather conditions) could affect the outcome of the game. As many bookmakers don't have enough information on the game and can't accurately balance the action as it comes in, circled lines can't be added to a parlay. Some online or Las Vegas sportsbooks may have too much action on one side of the game and even with a line move they cant attract action on the other team. Most sportsbook business models are set to attempt to balance trade on all games and protect their bottom line. Most sportsbooks try to attempt to have all of their lines un-circled. The red box may be removed closer to the start of the game.