Marginal gains are a key component to success across elite sport and each season, Premier League clubs seem to invest more resources into this aspect of their coaching practices.
One by-product of this process is the increasing number of specialist set-piece coaches working in English football.
Across the last five top-flight seasons, an average of 21.5 per cent of goals have been scored from set-plays.
So, while there has been a gradual decline in their importance since a peak share of 28.2 per cent in 2009/10, it is an area that clubs are rightly targeting in search of an edge.
Do set-piece coaches make a difference? Well, at three of the Premier League’s biggest clubs, there is strong evidence of progress in this department.
Barry improving Chelsea
Anthony Barry is one of the rising young stars in the coaching world, excelling in senior roles with Chelsea and Republic of Ireland.
After three years assisting Paul Cook at Wigan Athletic, Barry joined Chelsea in the summer of 2020 as an assistant coach to Frank Lampard.
One of the main parts of his brief was to improve the Blues' poor record from set-pieces in both the defensive and attacking phase.
Chelsea set-piece comparison
| 2019/20 | 2020/21 | 2021/22 | |
| Set-piece goals | 11 (10th) | 12 (5th) | 10 (2nd) |
|---|---|---|---|
| Set-piece goals conceded | 14 (14th) | 7 (4th) | 3 (3rd) |
Chelsea's performance levels from set-pieces have been on a consistently upward curve ever since Barry took over responsibility for them.
Devising a series of innovative training ground moves and finding a formula that helps repel corners and free-kicks, his ideas have been a roaring success.
Bettinelli praise
Chelsea goalkeeper Marcus Bettinelli reserved high praise for the 35-year-old in an interview with The Athletic in December.
"He [Barry] takes a lot of the set-piece training, he always gets the lads at it. What he brings to the team is priceless," Bettinelli said.
"It is very important to have that set-piece coach, but that is not all he does. He coaches us on a daily basis alongside the manager and the other staff. It's all one big team.
"He will split sessions so one day we'll be concentrating on defending set-pieces, another will be on attacking set-pieces.
"It all depends on the opposition. There will be teams who do different set-ups and are vulnerable in certain areas. Anthony's expertise is looking at that with the analysis guys and seeing where we can find an edge.
"We have scored from set-pieces this season because of Anthony's ideas. The manager acknowledges that. It's crucial because that set-piece could win us the game and that's down to him."
Highly regarded by Thomas Tuchel, Barry is viewed as an outstanding analyst and somebody who is very comfortable taking sessions.
He has been strongly tipped to become a head coach in the future, having reportedly turned down several managerial offers from EFL clubs already.
Jover's instant impact
Arsenal hired Nicolas Jover from Manchester City last summer to replace outgoing set-piece coach Andreas Georgson and the Frenchman has made a tremendous impact.
Turning a glaring weaknesses (attacking set-pieces) into a major strength, the Gunners have already scored two more set-play goals from 21 matches this term than they did in the entire 2020/21 campaign.
Almost a quarter of their goals have stemmed from corners or wide free-kicks, compared to less than 10 per cent prior to Jover's arrival.
Arsenal set-piece comparison
| Arsenal 2021/22 | Total | PL rank |
| Set-piece goals | 8 | 4th |
|---|---|---|
| Set-pieces xG | 6 | 12th |
| Set-piece shots | 76 | 8th |
| % Goals from set-pieces | 24.2 | 8th |
| Arsenal 2020/21 | Total | PL rank |
| Set-piece goals | 6 | 17th |
|---|---|---|
| Set-pieces xG | 7.1 | 19th |
| Set-piece shots | 110 | 18th |
| % Goals from set-pieces | 9.16 | 19th |
Six of those strikes have come from corner kicks (double last season's tally) with 40-year-old Jover a big fan of crowding the six-yard box.
In a home win against Southampton, Arsenal filled that domain with bodies to leave a 1v1 for Gabriel to exploit by making a late near-post run.
At Leicester City, Arsenal created a distraction by shifting four players to the far post, leaving Ben White and Gabriel in a 2v2 on the penalty spot.
Using White as the blocker, his contact with Youri Tielemans cleverly opened a pathway for Gabriel to attack, again at the near post.
In a 3-1 success against Aston Villa, Jover's plan to use the penalty spot 2v2 as a decoy worked beautifully.
Instead, two players broke free from the melee inside a crowded six-yard box where Thomas Partey nipped in ahead of a zonal marker stationed at the near post.
Arsenal's new set-piece coach has shown great ingenuity with his plans this term.
Liverpool's marginal gains
Jurgen Klopp is a huge advocate of innovation around marginal gains, employing Thomas Gronnemark as a throw-in coach, and using surfer Sebastien Steudtner to work on breathing exercises for his players.
Last summer, the Liverpool manager enlisted the services of neuroscientist Dr Niklas Hausler and his business partner Patrick Hantschke to fine-tune the mental state of his set-piece takers.
Their methods had proved a success in basketball, golf, darts and archery and they have now developed a training programme dedicated to footballers in dead-ball situations.
"We developed a whole training procedure and analysis to improve mental states and as a result increase precision. That's what we call our 'neuro11' brain training," Dr Hausler told The Athletic last October.
Using electrodes to gather player-specific data the use of science has been embraced by squad and coaching staff.
"Jurgen and I really believe in these two guys and their concept. We believe in the stimulus they give," said assistant manager Pep Lijnders in the same interview.
"They give the right input for players to find the right flow and, with this, more accuracy. They help with putting the players in the right frame of mind and how to reset."
Teams with most goals and shots from set-pieces
| Most set-piece shots | Most set-piece goals | ||
| Liverpool | 122 | Liverpool | 12 |
|---|---|---|---|
| Man City | 105 | Man City | 10 |
| Brentford & Chelsea | 97 | Chelsea | 10 |
Has it worked?
Well, four clubs scored more set-piece goals than Liverpool last season, but they currently top the rankings with 12 strikes, the same as they managed in total last term.
They are also by some distance the team who have had the most efforts on goal from dead-ball scenarios.
Averaging over five shots per match from set-pieces, with 16 matches left to play, they are just 17 set-piece attempts away from matching last season's tally.
This success and that of Barry and Jover is likely to encourage more clubs to bring in specialist coaches to focus on set-piece routines next season and beyond.
In a sport that is embracing the importance of fine margins, this is a growth area that looks ready to explode.