Head Ball 2 always tries to find an equal opponent for you. To do this the system first checks your account level and your average success in Head Ball 2. As a result of these parameters, it will pair you with the most suitable opponent.
For example, if you are level 45, it will look for the players in +/- 5 level range. In this case, your opponent will be a player between 40 and 50. If you are constantly winning your matches, you are likely to be matched with an opponent that is stronger or equivalent to your strength.
If the system cannot pairs you with a real player, you will be paired with a bot that meets your criteria.
You can defeat tough opponents by upgrading your characters, using super powers, or even better accessories.