Professional gamblers can do it and can make a good living from it.
Team managers to some extent need to do this in order to plan a team's season, knowing which games to focus on and which ones to leave more to hope.
Some sports journalists also have the knack of getting it right more often than not.
To some it may seem like guess work or going on gut feeling but there is a science to sport and if you know what factors are important you too can be successful at predicting match results.
League position The first and most obvious thing to look at when deciding who's most likely to win a game is the relative position of the teams in the league table.
If there are a number of places separating the two teams then the higher team is most often going to win and if the teams are close together then a draw is the probable result.
You can do this by rule of thumb or it is possible to be more methodical by going back through the records and quantifying just how much of an advantage the league position is.
Over the last five years in the English Premier League for example, when the two teams are within 6 places a draw is on average the most likely result.
Different leagues will vary depending on how competitive they are and it will also vary at different points in the season.
League position is less effective a predictor at the start of the season when there aren't enough results to make a reliable prediction; and also at the end of the season when teams (particularly the more successful ones) are tired! Home or away The next most important factor to consider is whether a team is playing at home or away.
In some leagues away victories are relatively rare.
The main reason for this is the influence of the crowd.
For teams that have a long way to travel and few supporting fans the opposition stadium can be a hostile environment.
Also (although of course it shouldn't happen) the crowd can have an influence on the referee.
Refereeing is full of marginal decisions, and the presence of a large crowd of jeering supporters can effect the referee's judgement.
This effect of 'home bias' by referees has been scientifically tested by analyzing match videos, and has been shown to be a genuine phenomena - not just a frustration in the minds of the disappointed away fans! Because of this home advantage teams will often have two configurations: one for home and one for away.
Away teams will often be more cautious and play a defensive mid-fielder in place of one of the strikers, making an away victory even less likely.
It's easy to quantify the home advantage in a league by adding up all the home wins over a season and comparing it with the number of away wins.
The ratio is typically around 2 to 1 in favor of the home team.
Who's playing? A key decider is the team announcement.
When the line up of the teams is announced, usually twenty minutes before kick-off, this gives a big indication of how the game will go.
The team sheet will tell you two things: firstly whether the manager is playing his best team (e.
g.
are there players out through injury? Or is he saving players for a more important match?).
Secondly it will tell you the likely formations.
If a team has no recognized striker then they are probably going to be playing a more defensive formation.
However, if there are a number of strikers on the substitutes' bench then it is likely the coach will be putting them on the pitch at a later stage in the game and thus is not settling for a draw.
Also look out for players just coming back from injury.
Such a player may have a good first game but performances may then dip as fitness becomes an issue.
Typically it takes 5 games for a player to get back to full match fitness.
Who's on a roll? As with many sports, confidence is a huge factor.
Teams can get into cycles where bad results leads to bad confidence which in turn leads to worse performances.
The same is true when a team's confidence spirals upwards.
It is for this reason that teams tend to go through good and bad patches.
When a team is on a winning streak there is a strong likelihood they will continue winning, even against better teams.
Look out for runs in a team's recent matches: e.
g.
how many games have they gone without a victory? Although they won't often admit it players are acutely aware of these statistics and it does play on their minds.
Other runs to look out for are:
- Games without scoring a goal
- Number of clean sheets (no goals against)
- Consecutive away wins
- Number of games unbeaten
- Number of games played
Tiredness is an important factor in determining a team's chances of winning.
A player should normally be able to play 2 games a week but this is hard to sustain over a number of months, especially if there is a lot of traveling and the games are very competitive.
A team that has not played for 7 days has a significant advantage over one which has played in the last 3 or 4 days.
Derbies and rivalries Some matches have a special significance for supporters and players alike.
Derby games, where the two teams are local to each other, can throw up unexpected results.
Part of the reason for this is that the away supporters don't have far to travel and so can be in the stadium in equal numbers to the home fans.
This can create an unusually vibrant atmosphere which can make players more nervous and accident prone.
The intense rivalry between such teams can produce special performances from some teams.
This all makes it hard to predict the outcome of such games.
There can be other team rivalries that one should also be aware of: for instance teams that have a history of victories over one another in important competitions; and teams that have an equal number of trophies.