Friendly matches are played usually during pre-season. To many people, these are very meaningless matches as the teams are just there to kick the ball around for fun. No trophies, no qualification, nothing. But these games can also be profitable if you know what to look out for.
A few weeks before the new season starts, you'd be able to find matches with, a very strong team against a much weaker team. Like...let's say Barnet vs Arsenal. Arsenal play away. Barnet FC plays in League Two(England). I'm not saying Barnet is a bad team but they only have 1 imported player. And with Arsene wanting to test out his new buys(it was in the news), and guys like Arshavin and Nasri playing on that day. Barnet simply don't have too many chances.The game ended with a 4-0 defeat over Barnet.
But watch out, some of these matches may end up as a draw. Like...for example on July 17th 2010. Tottenham Hotspurs playing away in San Jose, California. The Earthquakes are an "okay" team in the MLS. But Tottenham were the favorites. The game ended with a 0-0 draw. So, I checked for updates on the Spurs website. Looks like the guys are in California playing baseball, they've got pictures posted too.
News and updates are very important. Little details on what your team is doing and their intention for the match that you are betting on, can go a long way
