Every node that has a defender has three attack bonuses. You lose one attack bonus per death. Once you teach 0 attack bonuses/die three times on a defender, the deaths don't matter anymore.
If there is no defender on a node but there could be one (ie they just didn't place one), then you automatically get the 3 attack bonuses.
If you want to know the exact amount of bonuses you lost, count every bonus around the map, and if your death count is higher than the amount of bonuses you actually lost, those deaths dont count. Though you should really talk to your alliance about tkos.
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If there is no defender on a node but there could be one (ie they just didn't place one), then you automatically get the 3 attack bonuses.