Complex sentence: The role of a Scotland national football team manager was first established in May 1954 with the appointment of Andy Beattie, who took charge of six matches before and during the 1954 FIFA World Cup, when Scotland competed at their first major tournament.
Split into simpler sentences: The role of a Scotland national football team manager was first established in May 1954, when Andy Beattie was appointed. Beattie took charge of six matches before and during the 1954 FIFA World Cup, when Scotland competed at their first major tournament.