NGR (Net Gaming Revenue) is GGR after deductions. It is the number that speaks to margin and therefore the one that usually pays affiliates and appears in contracts.
The critical point: there is no single definition of NGR. Across operators you see at least four variations, with and without tax, with and without payment fees, with and without provider royalties, with bonus cost at face value or at converted value. Comparing two companies' NGR without aligning the formula produces wrong conclusions.
In affiliate contracts, the NGR formula is the item that generates the most commercial disputes. The practical recommendation is to attach a closed list of deductions to the contract, with percentages or caps where variable, and to state what happens if a new deduction is created later.
When reading any public NGR benchmark, the first question should be: what exactly is deducted here?