How Liverpool transformed their corner threat

Arne Slot welcomed Liverpool's set-piece efficiency in their 1-0 win over Sunderland at the Stadium of Light. "Usually we concede one, but tonight we could score and that's the difference for us in this game," he said in his press conference.

Virgil van Dijk's goal, headed in from Mohamed Salah's delivery in the second half, was actually Liverpool's third from a corner in their last four Premier League games. But their overall total of four this season remains the fifth-lowest in the Premier League.

Slot referenced the cost of failing to capitalise on set-pieces in marginal games earlier this season, citing their draws with the other newly-promoted teams, Leeds and Burnley. So, what's changed?

Embracing the inswinger

Their newfound effectiveness is not a coincidence.

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Instead, it is a result of a drastic change of approach.

Prior to last month's defeat to Bournemouth, when they scored the first of their three recent goals from corners, Liverpool had the lowest percentage of inswinging deliveries in the Premier League, at 49.4 per cent, well below the average of roughly 70 per cent.

In the four games since, their percentage has shot up to 82.5 per cent, with 28 of their 34 corners against Bournemouth, Newcastle, Manchester City and Sunderland having been inswingers.

The change of emphasis, which, coincidentally or not, follows the departure of set-piece coach Aaron Briggs at the end of December, has clearly proved fruitful, with Liverpool scoring three times from 34 corners having only scored once from 117 previously this term.

It is worth noting that even the one goal scored before the change of emphasis, in the win over Brighton on December 13, resulted from an inswinging delivery from Salah for Hugo Ekitike.

That goal from Ekitike, like the ones scored by Van Dijk against both Sunderland and Bournemouth, was scored from inside the six-yard box and highlighted one of the main advantages of the inswinging delivery: that its trajectory facilitates closer-range shots.

It is not an exact science. There are of course other factors to consider. But generally, the closer you are to goal, the higher your probability of scoring. By using more inswingers, Liverpool have been able to target the six-yard box far more frequently.

A comparison between their corner locations before and since the game against Bournemouth shows the percentage increase of deliveries into more dangerous areas, with a clear focus on the centre of the six-yard box, right on top of the goalkeeper.

The popularity and greater effectiveness of inswinging corner deliveries is evident up and down the Premier League, with five per cent of all inswinging corners having led to goals this season, compared to only 3.6 per cent of outswingers.

Packing the six-yard box

It is not just about the zones targeted from corners.

How those zones are occupied is similarly important.

It has become increasingly common to see Premier League sides station a throng of players inside the six-yard box from attacking corners, maximising their chances of winning the first contact at close range while also making it more difficult for the opposition goalkeeper to catch or punch the delivery.

The approach, coined the "meat wall" by analyst Michael Caley, has been used to good effect by Arsenal and has now been adopted by Liverpool too, with Van Dijk one of five Liverpool players inside a crowded six-yard box when he headed in against Sunderland.

The goal came from Liverpool's 10th corner of the night but the same approach had been evident earlier in the game too.

Ten of Liverpool's 11 corners in total were inswingers, the only exception being a short corner taken by Salah as they sought to wind the clock down in stoppage time.

For their first corner of the evening, shown below, Liverpool's players started their runs outside the six-yard box. But after that delivery from Salah was easily headed clear by unopposed Sunderland centre-back Dan Ballard, Liverpool changed tack.

From then on, they had a minimum of three players inside Sunderland's six-yard box for every corner.

These deliveries proved far harder for Sunderland to defend, with Van Dijk heading a Cody Gakpo delivery over the bar and Ibrahima Konate nearly getting on the end of another Gakpo centre before the approach finally paid off for the decisive goal.

The success of the approach, exemplified by Van Dijk's goal, helps to explain why Premier League teams are directing corners into the six-yard box with increasingly regularity.

In fact, the number of corners into the six-yard box has risen in each of the last five Premier League seasons, reaching a high of 4.72 per game in the current campaign as growing number of teams, including Liverpool, try to maximise their chances of set-piece success.

For Slot, the result is a victory from a game his Liverpool side might previously have drawn, with hope of more improvement to come.