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.
His handling of the reins was superb, and the horse responded well.
The project management didn't go well, and the team got confused.
Common spelling using kana for さばき; the kanji 捌き is also used but less frequent.
Kanji spelling for さばき; less common than the kana form.
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.