Deductions & credits

I have not signed any form.  He claims the IRS stated that he has the right to claim her based on divorce decree alone.  Which this would be his year, however, the only support he has given this child is the child support.  I am the custodial parent who provides 99% financial support and the child lives with me.  She has spent 5 nights in 5 years with her father.  So what benefit does he have to claim  her? Doesn't he have to state she lived with him?