tight five

US /ˌtaɪt ˈfaɪv/
UK /ˌtaɪt ˈfaɪv/
"tight five" picture
1.

a group of five players in a rugby union scrum, consisting of two props, a hooker, and two locks

:
The coach emphasized the importance of a strong tight five for winning scrums.
A dominant tight five can set the platform for attacking plays.