No manager will ever be able to replicate the legacy Sir Alex Ferguson forged at Manchester United. His legendary stint as manager saw him completely overhaul the Red Devils from his 1986 arrival, re-establishing them as a footballing giant and dominating the modern era English football.
He retired in 2013 having won 13 Premier League titles, five FA Cups, two Champions Leagues and countless other accolades, closing the curtain on a sustained era of dominance that will likely never be matched by any one manager.
By the end of his tenure, the club was run around Ferguson, explaining why United have struggled so significantly in the time since his retirement.
From style, to attitudes, to recruitment, Ferguson left his mark everywhere. The Scotsman was always able to make the signings he wanted to from the moment he arrived, as was the norm in football in previous years, but maintained that control over incomings and outgoings over the years to come, developing an incredible eye for talent and taking players well beyond their potential.