Why Celtic must adhere to the dos and don'ts of getting the ball in the box

This season, under Ange Postecoglou, the team have attempted a 14 per game. In fact, in the three recent matches against Dundee, Hibs and St Mirren, they attempted 18, 23 and 26 crosses respectively. 

Studies have shown that it can take an average of at least 76 crosses to score a goal and therefore it can be seen as an inefficient method of attacking. As a result of facing defensive setups, Celtic often have little choice but to attempt to create chances in this suboptimal manner but, of course, not all crosses are exactly the same as one another and there are ways to improve their chances of scoring from this method. 

The late Garry Gelade, in his 2017 OptaPro Analytics Forum presentation, noted eight different zones that crosses originate from - four on the left flank and their mirror images on the right side - and recorded the ideal start and end points of a cross. He concluded that a zone that stretched vertically from the edge of the penalty area to the goalline and horizontally from just outside the penalty area to just outside the six-yard box was the best starting location for a cross.

His analysis showed that crosses from this area within the penalty area should be aimed between the penalty spot and the goal and ideally towards the far post. 

Football analytics journalist Tom Worville, now a data scientist for German Bundesliga side RB Leipzig, built on this work in 2021 and analysed the conversion rate of crosses from 16 different zones of origin - eight per flank.

Similarly to Gelade, Worville found that crosses which originated from a section of the halfspace - starting just before the penalty area and ending just before the six-yard box vertically, and starting just outside the penalty area and ending just before the six-yard box horizontally - had a scoring conversion rate of 2.1 per cent and were the most dangerous. The least dangerous origin of delivery for a crossed chance, with a scoring conversion rate of just 0.7 per cent, was wider and deeper than the corner of the box.

The image above shows Josip Juranovic attempting a cross, against Hibs, from the least dangerous of those zones. Ryan Porteous averages just less than six clearances per match but he made 13 clearances in this game and many of those were from under-hit crosses by the Croatian right-back delivered from not very threatening areas. 

The poor deliveries by Juranovic continued for much of the next fixture versus St Mirren, although interestingly they tended to be over-hit rather than under-hit this time around. Even when Juranovic did manage to cross from a good area, as shown in the image above, his technique failed him.

READ MORE: Do Celtic actually have a low-block problem?

Against Hibs, Juranovic created just 0.03 Expected Assists (xA) and against St Mirren he completed just one of his six attempted crosses. Juranovic is fairly skilled in striking the ball, as shown by his proficiency at penalties, so with a training ground focus on crossing locations and delivery, this could be converted to a real strength for Celtic. 

Jota attempted the most crosses of any Celtic player in each of the three matches in this study; 11 against Dundee, nine versus Hibs and seven when facing St Mirren.

His choice of where to cross from, his technique when crossing and the areas he delivered the ball into were all generally excellent. The image above shows a cut-back type cross he made from statistically the second most dangerous of the crossing zones which resulted in a 0.32 xG chance for Liel Abada.

While the creativity of the central attacking midfielders in the side has hit a slump recently, the Portuguese winger has been consistent - with 0.36 xA per 90 as an average during this three-match stretch. 

Greg Taylor has been reticent to attack at times, and seems particularly averse to overlapping, but he did create a chance against Hibs from the most desirable bit of crossing real estate. His cross led to a 0.40xG chance for Abada and the more Taylor, and his fellow full-backs, can be encouraged to cross from these areas instead of deeper, wider zones then the better it is for Celtic. 

In injury time against Hibs, Reo Hatate demonstrated that this is also an area Celtic’s central attacking midfielders can impact as he delivered an excellent cross from the second most dangerous zone which landed in the far post space which Gelade has shown is most likely to lead to a goal. 

Celtic’s eventual goals against St Mirren both came indirectly from crosses as first Cameron Carter-Vickers and later Callum McGregor pounced on second balls to score. 

Gelade analysed the likelihood of this happening and found that when including the indirect effects of a cross, such as goals scored from the second ball, corners and penalties conceded, it needs only about 45 crosses to produce a goal on average. 

Worville was able to demonstrate that the chance of a goal occurring within six seconds of a cross had a not insignificantly higher probability than it happening directly from the cross. Juranovic’s original cross shown above comes from an area with a one per cent chance of conversion but this is increased to 1.5 per cent when considering goals, such as McGregor’s, which happen within six seconds of the delivery.  

Crossing is declining year on year in elite football, perhaps as teams get wise to its inefficiency, but done right it can still be a useful element of a side’s approach to scoring.

It’s beneficial not to be one-dimensional and to have goals from all types of attack, even long shots and crosses, within your repertoire.

Celtic just need to maximise their efficiency by crossing from the most optimal areas, ensuring whoever is playing at centre forward is coached to make good runs in the box and being ready, in numbers, to score in the aftermath of the initial cross.