In terms of strategy, Nagamasa negotiated with warlords of the western squad such as Hideaki KOBAYAKAWA and Hiroie KIKKAWA in order to have them switch sides; and due to such achievements, he was granted 523,000 koku in Chikuzen Najima (Fukuoka) by Ieyasu after the war as having rendered the most distinguished service.
長政は調略においても西軍の小早川秀秋や吉川広家など諸将の寝返りを交渉する役目も務めており、それらの功により戦後、家康から一番の功労者として筑前名島（福岡）に52万3000石を与えられた。