Moving to a three-man defence at the 2018 World Cup was widely acclaimed as a masterstroke by Gareth Southgate. The jury is still out, however, on whether returning to a similar shape will prove equally effective when it matters most.

As a disciple of former Three Lions boss Terry Venables, Southgate is perhaps inevitably drawn to a back three in the search for greater stability and optimum balance, and there have been signs that Southgate's 3-4-3 system can cause the best teams problems, not least in the second half of Sunday's 2-0 defeat to Belgium. England probed the Belgian defence for long periods, albeit without testing Red Devils goalkeeper Thibaut Courtois with any great frequency.

Jack Grealish was the biggest plus by some distance, growing in confidence and influence as the match wore on. He was the most fouled player in the opening 20 minutes and by the end Belgium couldn't even get close enough to him to bring him down, one sublime turn leaving Thomas Meunier for dead exemplifying the ease with which he took to his first start in a competitive international.

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The 25-year-old carried the fight as Belgium sat camped on the edge of their own box, content with their two-goal advantage, and England's system enabled the Aston Villa midfielder to be so prominent the visitors inability to score was partially explainable by poor execution from promising positions rather than a complete absence of creativity.

"I'm not sure we could have been any more creative than we ended up tonight," said Southgate postmatch. "We ended up with five -- two attacking wing-backs, three attacking forwards. I think we showed against Wales and Ireland you can score goals with the system. Against the very best teams, the games are tight. Personally, it gives me more belief. As a manager, you've got to focus on performance and if you play at the level we did tonight, you'll win more games than you lose.

"It has been helpful for Jack to bed in with the group so he knows the way we want to play and the players get an understanding with him. Today was a great game for us to see him in and I couldn't speak highly enough of his performance."

However, the stability and balance Southgate aimed for was largely absent in the first half, which ultimately lost them the match. They were too conservative with the ball in midfield, an issue rectified in part by Harry Winks' introduction as a half-time substitute for Jordan Henderson, who reported muscle tightness and "felt he couldn't carry on" according to Southgate, no doubt setting off further alarm bells at Liverpool who have already lost Joe Gomez to a serious knee injury during this international break.

And mitigation should be offered in the form of notable absentees, Marcus Rashford, Harry Maguire, Raheem Sterling and Trent Alexander-Arnold among them.

But even with those players available, there is growing evidence that the 3-4-3 shape does not maximise England's strengths, chiefly the rich array of attacking talent that this time last year had many arguing England possess one of the best forward lines in world football.

After reaching the Nations League semifinals in a 4-3-3 system in June 2019, Southgate persisted with the same formation in the autumn and winter fixtures last year.

Those six games yielded five wins with 26 goals scored. The opposition was modest -- Kosovo and Bulgaria twice, Montenegro at home and Czech Republic away, the one game England lost in that run when Southgate tweaked the shape to a 4-2-3-1.

Since adopting a 3-4-3 system, England have taken one point from six against Denmark, secured a somewhat fortuitous win against Belgium and beat two severely under-strength teams in Wales and the Republic of Ireland.

This is not to suggest Southgate should abandon course. Indeed, their performance in defeat to Belgium was arguably the most threatening of the 2020-21 season, but England are out of the Nations League after scoring just three goals in five games.

Southgate argued England were simply unfortunate to lose here. Youri Tielemans' 10th-minute opener benefitted from a helpful deflection off Tyrone Mings and, although Dries Mertens' 23rd-minute free kick was superbly executed, Declan Rice was harshly punished for a tackle on Kevin De Bruyne which led to the opportunity to shoot at goal.

And England will rue Harry Kane having a header cleared off the line by Romelu Lukaku at 1-0, Kane testing Courtois in the first half and then failing to make the most of three shooting opportunities in the second, but ultimately this adds to the growing list of disappointing results against the top sides.

Southgate claimed pre-match that England need to "hunt down" the best sides but it is difficult to escape the conclusion at present that they have sacrificed too much attacking potency in an attempt to find greater solidity -- and the latter is not yet forthcoming.

A reminder of Southgate's commitment to 3-4-3 came in his substitutions, introducing Dominic Calvert-Lewin and Jadon Sancho, yet still refusing to change shape. Calvert-Lewin played wide right, despite operating as a central striker for Everton, while Sancho was deployed as a right wing-back, a first in his formative England career.

The best impact off the bench came from Bukayo Saka, a persistent menace down the left when introduced for the injured Ben Chilwell seven minutes before the interval.

The changes gradually sought to resolve a lack of pace in attacking areas in the first half which left England looking unduly blunted as Kane dropped deep -- a trait he now does so effectively at Tottenham -- only for an absence of runners in behind the Belgium defence to service.

This is not a criticism of Grealish or Mason Mount specifically, but it is a different story for Kane at Spurs with Heung-Min Son the most obvious beneficiary and perhaps it would be again if Sterling, Rashford or Sancho had started here.

"We had a different profile of players for sure but in those positions, I thought Jack had an outstanding game and he is a different sort of a player," Southgate said.

"As a different sort of a threat, we knew we had players that needed to come to the ball but with losing Raheem and Marcus we lost a lot of speed up front. Tonight we didn't quite have that but I can't fault the attacking play, probably up to the last chance or last pass a couple of times but we created far more opportunities than we did [when beating Belgium 2-1 in October] at Wembley."

Of course, the overall picture remains a work in progress. After Wednesday's Nations League match against Iceland, Southgate will have four months to scrutinise and evaluate the flurry of internationals condensed into a short timeframe.

And Grealish's performance against Belgium was a reminder that England now possess more than handful of talented individuals capable of imposing themselves on the best teams around. But turning that into a winning tournament formula remains the challenge.