"Change sides" is a phrase that can be used in many different contexts, from sports to politics. However, sometimes using the same phrase repeatedly can make your writing or conversation sound repetitive. Here are some alternatives to "change sides" that you could use instead:
1. Switch teams
2. Flip sides
3. Convert to
4. Defect to
5. Adopt a new position
6. Transition to
7. Join the other side
8. Turncoat
9. Switch allegiance
10. Swing to the other side
Using synonyms for "change sides" can add variety and interest to your writing or speech, making it more engaging for your audience.