The System (Gaelic football)

Donegal's winning of the 2012 All-Ireland Senior Football Championship was described as "one of the great GAA managerial coups" in history.

[5][6] Admirers of "The System" from other sports reportedly included Europe's 2014 Ryder Cup captain Paul McGinley and the soccer manager Neil Lennon.

"[8] Malachy Clerkin, writing in The Irish Times on 27 December 2012, described Donegal as "the alpha, the omega, and everything in between [...] just a sheer joy to watch".

When you consider the opposition – Cavan, Derry, Tyrone, Down, Kerry, Cork and Mayo – you can't but marvel at the achievement.

The top teams in Gaelic football— Tyrone, Kerry and Cork, who had dominated the sport over the previous decade — have been made to appear merely ordinary, and have been swatted aside with relative ease.

Donegal deployed The System to devour the heavily fancied Cork team and progressed to their first title decider since 1992.

[12] Tyrone's three-time All-Ireland winning manager Mickey Harte, attempting to analyse the game for the BBC, expressed his shock: "To be honest, I could not see that coming.

"[13] Donegal then unleashed The System on Mayo in the 2012 All-Ireland Senior Football Championship Final, rendering them motionless with two early goals and keeping them scoreless for the first sixteen minutes of the match.

Mayo's Kevin Keane fumbled, dropping the ball into the path of Colm McFadden who promptly slotted it into the back of the net for a second Donegal goal.

[15] McFadden, who scored a total of 1–03 for Donegal in the first half alone, was soon through on goal again, only for Mayo goalkeeper David Clarke to block the strike.

"[21] His teammate Ciarán Sheehan said in 2014, "I played against Donegal in the All-Ireland semi final a few years back, their power and fitness was something else and unfortunately we couldn't match them.

[12] Less than a year before McGuinness led his team to All-Ireland success, Vincent Hogan branded him "a leader of sheep" in a famous newspaper article.