noun
handling of the reins; control; management
Literally refers to the skill of handling reins, but commonly used figuratively for how well someone manages or controls a situation, project, or people.
彼の手綱さばきは見事で、馬がよく言うことを聞いていた。
His handling of the reins was superb, and the horse responded well.
プロジェクトの手綱さばきがうまくいかず、チームは混乱した。
The project management didn't go well, and the team got confused.
Compound of 手綱 (reins) and さばき (handling, from the verb 捌く 'to handle skillfully'). The figurative sense extends the idea of controlling a horse to managing situations.