Tactical flexibility, long a hallmark of Michael O’Neill’s management style, became his downfall on Sunday, as his Northern Ireland side lost their opening fixture of Euro 2016 to Poland.

Despite preferring a 4-1-4-1 formation during qualification, O’Neill somewhat surprisingly plumped for the back three he first trialed during the March friendlies. Craig Cathcart, Gareth McAuley and Jonny Evans were all thought necessary to marshal lone striker Robert Lewandowski, flanked by League 1 wing backs Conor McLaughlin and Shane Ferguson.

Target man Kyle Lafferty led the line alone, in front of a diamond midfield with Derby County’s Chris Baird at the base and captain Steven Davis at the tip. Manchester United defender Paddy McNair played the fish out of water role on the right of the four.

Northern Ireland’s 1st half shape

This ultra-defensive 5-3-1-1 smothered the Polish attack in the first half, with eventual goalscorer Arkadiusz Milik’s 29th minute strike from range representing Adam Nawalka’s side’s first of the afternoon.

Northern Ireland’s only problem was McNair, who consistently failed to shuffle across to shut down left back Artur Jedrzejczyk. Luckily for O’Neill’s side, the Krasnodar full back is a converted right back, who was unable to avail of the many crossing opportunities presented to him. Nawalka was left to rue the absence of regular left back Maciej Rybus, who missed out on these championships due to injury.

Although McNair’s half-time removal was understandable, the tactical shift that went with Stuart Dallas’ arrival onto the field was less so. The introduction of the Leeds winger signaled a second-half shift to 4-1-4-1, which the Poles immediately took advantage of. Jakub “Kuba” Blaszczykowski invaded the space that Ferguson, now on the left of midfield, would have filled in the first half. Milik availed of one less centre back body in the centre of the pitch to collect his cross and finish past Michael McGovern.

Northern Ireland’s shape at the start of the second half

O’Neill then went on to make two further futile changes to his side’s shape in a bid to get back into the game. First, Queens Park Rangers striker Conor Washington was introduced from the bench to join Lafferty up top in a 5-3-2. This switch back to a five-man defence saw Dallas asked to plough the lonely left wing back furrow. He immediately got caught out of position, with Northern Ireland lucky that Lukasz Piszczek failed to convert a gilt-edged opportunity.

Finally, with 13 minutes of normal time remaining, O’Neill removed his holding player Baird and introduced Nottingham Forest’s Jamie Ward behind the strikers in a 5-2-1-2. Through all these bewildering alterations, Northern Ireland’s non-existent attacking threat failed to improve. A McAuley header and a speculative Lafferty bicycle kick were their only two shots on goal; neither were on target.

Post-match, O’Neill copped out by claiming that his side were “overpowered” by a “better team”. While this is undoubtedly true, the Northern Irish manager should also look in judgement at the unnecessary half-time tactical shift that opened the door to his more weaponed opponents. O’Neill also suggested that the “personnel and system” may change going forward. Whatever Northern Ireland’s chances of turning around their French adventure after this defeat, their tinkering coach is unlikely to let us down on that front.