Ireland's chequered history with three at the back 

Ireland have played 25 times in the modern era with three centre backs

Matt Doherty, left, and Seamus Coleman of Republic of Ireland during the FIFA World Cup 2022 qualifying group A match between Serbia and Republic of Ireland at Stadion Rajko Mitic in Belgrade, Serbia. Photo by Stephen McCarthy/Sportsfile

How often have Ireland started with a back three?

The fixture in Serbia on Wednesday night was the 25th time (16 matches during Mick MCarthy's two spells, eight under Martin O'Neill and once under Stephen Kenny). Ireland have recorded 5 wins, 8 draws and 12 defeats with this defensive system in place.