When it comes to betting on the World Cup, most people know that there is a big difference between betting on round robin games and those in the round of 16 and beyond. From a betting perspective, though, there are just as significant differences between the first two games of the round robin and the third and final game. By understanding those differences, bettors can avoid costly mistakes, and they can often open up opportunities for real value. Here are four of the biggest differences:

Different motivations: The best team doesn't always win the third-round games for one simple reason above all - quite often they don't care to. It is possible for teams to secure a spot in the second round of the tournament after just two games - seven teams have done it in 2014. Those teams might not be nearly as concerned about their third game as they might otherwise be - especially if they have secured first place already or if there is no real advantage in terms of elimination round pairings for finishing first or second. Those teams could be much more interested in staying healthy and out of yellow or red card trouble than they are about winning. They could use the game more to work out specific problems exposed in the first two games than to try to win, and they won't be eager to give their next opponents too many insights into what they are planning.

Sometimes, though, teams will be eager to play at full strength even though they have clinched a spot in the next round. Group B this year provides a perfect example. Both Netherlands and Chile had clinched their berths already, and both would have likely prefered to have an easier game after an emotional run. Neither could afford to do so, though, as the team that finished second in the group will face Brazil in the first elimination round game. That onus now falls on Chile's back.

On the flip side, there are situations where good teams have had very frustrating tournaments, and are going to be tough to trust in their final game with little to play for because all they likely care about is going home.

Above all else, then, when you are handicapping third-round games you need to look at what a win in this game means, whether a draw would be adequate, how crushing a loss would be, and what the effort level is expected to be as a result. The more time you spend doing this, the further ahead of the public you will be, and the bigger your edge will be.

Team familiarity: One of the biggest challenges for World Cup teams is to try to create unity and chemistry in a short time frame. Players play all over the world for their clubs, so there is rarely enough time for practice leading into these tournaments. Friendlies help, but they aren't the same as real game action. As a result, it's far from uncommon to see top-level teams struggle to find their 'A' game early in tournaments. By the third game, though, they have played twice at full speed, and have had plenty of time to review what happened and improve on it. They are used to the heat and the conditions as well. Teams that have looked sub-par early on may be a whole different squad in game three.

Two games to divert public attention: To ensure that teams give full efforts in their third game, FIFA schedules both third games from a group to be played at the same time. That way the effort of teams isn't dependent on the outcome of the other game. It's a very smart move. Oftentimes one of those games is much more attractive to the public than the other - higher-profile teams, more coverage, sexier implications, and so on. In those cases the other game can often be overlooked by public bettors and can therefore deliver some nice value as a result.

Second half situation can change: Even though the two games start at the same time, you can be sure that the teams know what is happening in the other game by halftime. In cases in which the outcome of the other game has a direct impact on the teams in this game, that knowledge can really change how games are played in the second half. If the other game has had a lopsided first half then it could impact this game significantly. If that lopsided result all but ensures advancement for a team - or essentially eliminates them - then their second-half approach will be different than the first half because the stakes are different.

Read more articles by Trevor Whenham