WHEN Celtic eventually took the lead against St Mirren on Wednesday evening, the sense of relief emanating from the stands at Parkhead was palpable. Up until that point, Ange Postecoglou’s men had seen plenty of the ball but had struggled to break through their opponents’ rigorous shape. 

It isn’t difficult to see why supporters were feeling a little uneasy. Employing a back five with two holding midfielders sitting in front of the defence, Stephen Robinson set his team up in the hope of clinging on and nicking a point without offering the slightest hint of attacking intent. 

Space in the final third was at a premium during the midweek contest – as it was during the goalless draw with Hibs in Celtic’s previous league outing – and it’s fair to say that the league leaders were having difficulty slicing their opponents open. The home crowd started getting a little antsy, knowing full well how damaging another two dropped points could be in the title race. 

Those concerns were assuaged 10 minutes into the second half when Celtic did something that has been pretty unusual without David Turnbull on the park: they scored via a set-piece. Jota’s whipped delivery from the right wasn’t adequately dealt with by the St Mirren defence, and there was Cameron Carter-Vickers to sweep the ball home on the rebound to give his side a priceless lead. 

Callum McGregor would go on to wrap up the win 10 minutes from time but it was the earlier set-piece that proved to be the Buddies undoing. It changed the atmosphere in the stadium, signalled a change in tone from the players on the park and turned the whole contest in their favour. 

Much like the recent stalemate at Easter Road, Celtic were asking probing questions from open play but weren’t making too many significant inroads. There wasn’t much concern of conceding – both St Mirren and Hibs were positively toothless in the recent encounters – meaning the matches quickly became an exercise in breaking down a well-drilled opponent. It was a test that Postecoglou’s team failed in Leith but they responded in good fashion against St Mirren. Quite simply, they had to find a different way of scoring and they did just that. 

Carter-Vickers’ goal the other night was overdue in a sense. Since the turn of the year, Celtic have scored twice from an attacking set-pieces. The first wasn’t exactly one off the training ground: Reo Hatate opened the scoring early on in the 3-0 win over Rangers last month when the initial cross from a corner was headed out to the midfielder on the edge of the box, who in turn lashed it in with a terrific strike. Giorgos Giakoumakis’ equaliser against Dundee last month, meanwhile, also came via a set-play. 

The win over St Mirren showed just how valuable proficiency from set-pieces can be but it is an area where Celtic have improved on Postecoglou’s watch. Under Neil Lennon, little credence was given to them and he team generally lagged behind the rest of their Premiership contemporaries in this regard. 

The same can’t be said this season. Celtic are comfortably the second-most effective team in the league in terms of producing goals from corners and are slightly under-performing their xG from such scenarios, while they offer more of a threat than most from indirect free-kicks in terms of goals scored. They are slightly below the league average but still offer far more than the likes of St Johnstone or Hibs. 

This presents us with a quandary. If we know that Celtic’s offensive set-pieces are better than most this season, why was Giakoumakis’ goal against Dundee the only dead-ball situation to have paid off since the turn of the year until Carter-Vickers’ goal on Wednesday evening? (Remember, Hatate’s wasn’t exactly a well-executed drill). 

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The answer can be found in Dingwall. You see, that wet and windy evening in December where Anthony Ralston leapt highest to steer the ball home in injury time and grab a momentous three points was another significant milestone in Celtic’s season. It was the last time Turnbull made a first-team appearance before a hamstring injury signalled the start of a stint on the sidelines. 

Turnbull’s deliveries from corners and indirect free-kicks have been a game-changer for Celtic this season, and their absence over the last couple of months has been telling. This season, Turnbull isn’t only his own team’s greatest threat from dead-ball situations. He also happens to be the league’s top performer, and can consider himself a little unfortunate not to have a few more assists to his name. 

The former Motherwell midfielder boasts the highest rate of key passes (passes that lead directly to a shot on goal) from set-plays of any Premiership player, averaging over two a game, and has a set-piece xG Assisted per 90 of 0.19 – a 25 per cent increase on his nearest challenger, Aberdeen’s Calvin Ramsey, and nearly double that of James Tavernier, the league’s fourth-best performer in this regard. 

It is a sizeable weapon to add to Celtic’s attacking arsenal and it is one that will be relied upon once Turnbull regains his fitness once again and restored to the starting XI. In tight, cagey matches against limited opposition who possess zero designs on attacking, effective deliveries from dead balls – or lack thereof – have often been the difference between success and failure. 

Almost every goal that Celtic have scored via a set-piece this season has been a meaningful one. Not all goals are equal (adding the fifth in a 5-0 rout isn’t quite the same as providing a last-gasp winner, for example) and Postecoglou’s team have developed a happy habit of making their set-plays count. 

Of the eight goals Celtic have scored via corners and indirect free-kicks in the league this season, seven have either been the winner or an equaliser. Between 10 and 12 points have been picked up (depending on whether you count the second goal in a 3-1 win over Hibs as a winner) from positions were Celtic would have likely missed out otherwise. 

It’s a massive contribution to the team’s title tilt and one that underlines the importance of Turnbull to Postecoglou. It is no coincidence that the vast majority of these goals have come from the playmaker’s deliveries and this contribution necessitates a hasty return to the starting line-up once he is fit and available once more. 

Wednesday night’s win over St Mirren offered Celtic a pointed lesson in just how important attacking set-pieces have been this term. The Buddies won’t be the last team to park the bus at Parkhead between now and the end of the season and Postecoglou will require different ways to hurt the opposition. Jota provided an answer midweek but in truth, Turnbull is the only Celtic player whose deliveries from set-pieces can be regularly relied upon. And if Celtic do manage to reclaim their Premiership crown, there won’t be many players to have had a more telling contribution.