In stark contrast to the successful radicalism of Northern Ireland manager Michael O'Neill, which yielded victory over Ukraine, the Republic of Ireland were comprehensively undone against Belgium by the innate conservatism of his namesake Martin.
Acting to fill the gap created by Jonathan Walters' Achilles injury, O'Neill opted against replacing the Stoke City striker with James McClean in a straight swap. McClean and Shane Long were thus denied the opportunity to reprise the high-pressing double act that featured strongly in tournament warm-up friendlies against Slovakia and Belarus in recent months.
Instead, the Ireland manager chose to replace Walters with Burnley left back Stephen Ward, a decision which shunted Robbie Brady forward, to play on the left of a very narrow midfield four. In a clear statement of negative intent, Long was asked to plough a lonely furrow up top in a 4-4-1-1.
Failing to learn the lessons of history, O'Neill had again succumbed to his safety-first mentality by ditching the diamond.
Since O'Neill first introduced the diamond formation at home to Scotland in June 2015, Ireland have failed to win any of the competitive fixtures for which it has been dropped. Visits to Poland and Bosnia in late 2015, in which 4-1-4-1 and 4-4-1-1 were used respectively, produced an uninspiring defeat in Warsaw and a fortunate draw in the fog of Zenica.
Home victories and clean sheets against technically superior outfits like Germany and the Bosnians demonstrated that the system was not ill-suited to encounters with opposition of the repute of Marc Wilmots' side. In the face of that evidence, O'Neill still unfortunately feared otherwise.
Although his compact and narrow defensive unit stymied the Belgian attack in the first half in Bordeaux, the threat it posed on the counter-attack was negligible at best.
The first pass out of defence was, more often than not, a speculative long-ball up to an isolated Long, who won a mere 25 per cent of his aerial duels and lost possession of the ball 10 times. With no strike partner to combine with, the Southampton man was completely reliant on a visibly toiling Wes Hoolahan to pick up the second ball in behind.
For the first time since the scoreless draw with Norway at the 1994 World Cup, Ireland finished a major tournament game with precisely zero shots on target.
Divesting his side of its second striker was not the only example of O'Neill's malign conservatism on display against the Red Devils. Keeping faith with James McCarthy, who abrogated his defensive responsibilities on the right of the diamond against Sweden, cost Ireland dearly.
Aside from the set-piece deliveries of Kevin De Bruyne, Marc Wilmots' side were at their most dangerous when given the rare opportunity to counter-attack at pace. McCarthy's ill-advised lunge at De Bruyne generously permitted the Manchester City midfielder to successfully lead one such opportunity at the start of the second half.
The Everton midfielder, who survived 85 minutes on the Stade de France turf against Sweden, erred again on the hour mark, when he failed to notice Axel Witsel running off him to head in Thomas Meunier's cross. O'Neill immediately acted with the haste he had lacked in Saint-Denis, removing the 26-year-old in favour of McClean.
Ciaran Clark was also extremely fortunate to retain his place in the side, after a complete loss of composure in the aftermath of Hoolahan's opener against Sweden. The defender failed to justify the faith shown in him by O'Neill, when his desperately unsuccessful slide tackle on the half-way line opened the door for Eden Hazard to feed Lukaku for Belgium's third.
In advance of Thursday's famous victory over the Ukraine, Michael O'Neill made five changes to the Northern Ireland side that capitulated to Poland in their Euro 2016 opener.
While it's true that Ukraine are no Belgium, the radical decision-making that won the day for the former Shamrock Rovers boss is clearly completely anathema to Martin O'Neill.
If his side are to rescue their Euro 2016 campaign against Italy, the Ireland manager needs to restore the diamond and dump the players that have failed him on the big stage. This is not the time to play it safe.