Sir Alex Ferguson introduced wing play and game management.
Pep Guardiola introduced tiki-taka.
Jürgen Klopp introduced gegenpressing.
Jose Mourinho introduced the low block and counter attacking football.
Carlo Ancelotti introduced Flexible Tactical System
Antonio Conte revolutionized the 3-5-2 / 3-4-3 system.
What exactly did Arsene Wenger contribute to football? 😭