First, it's important to understand what factors matchmaking is based on. Read "How does matchmaking work?" for details.
There can be a couple of reasons why a player is matched against strong opponents:
- Your opponent just gained a lot of power by upgrading their spells
- A player is playing with very high skill or has a very effective spell deck and has gained many skill ranks before.
- The opponent does not play to the full potential of their deck. These players get defeated more often and therefore lose many skill ranks. These players face lower level opponents and still might struggle to win.