Could this be the greatest World Cup of modern times? The question has been asked more than once amid the breathless excitement of the past fortnight. The goals have flowed and the drama has been extraordinary. So it feels prudent, if a little po-faced, to warn that we are approaching the point at which caution tends to take over.
This time four years ago we were rhapsodising about the World Cup in Brazil, which featured 136 goals in the group stage, comfortably breaking the record for a 48-game first phase. Yet that attacking freedom gave way to containment and tactical caution in the knockout stages.
The average number of goals per game dropped from 2.83 to 2.19 in the later rounds. Take Germany's freakish 7-1 semi-final win over Brazil out of the equation and that rate would have been 1.8 goals per game. Six of the 16 knockout games were goalless after 90 minutes. A festival of free-flowing football it was not.
The 1998, 2002 and 2006 tournaments followed similar patterns, with goals coming far more freely early on. The 2010 Finals bucked that trend after a dreadfully disappointing group stage, but otherwise the pattern has been clear.
Jock Stein, the late Scotland and Celtic manager, used to say that teams should wear their working clothes during qualifying for the right to wear a dinner suit at the Finals, but it often seems that a straitjacket is preferred when the stakes are highest.
Take Argentina in 2014. Albeit against Bosnia and Herzegovina, Iran and Nigeria, they swept their way to three wins out of three in the group stage, playing in a 4-3-3 formation with Lionel Messi scoring four times. In the knockout games, they switched to a more rigid 4-4-2 and beat Switzerland 1-0 (after extra time), Belgium 1-0 and the Netherlands on penalties (after 120 goalless minutes) before Germany beat them 1-0 after extra time in the final.
Recent convention suggests that, even if one team want to attack in the knockout stages, their opponents will be focused on stopping them.
That is often the reality of high-stakes football at a World Cup. Costa Rica were one of the stories of 2014 but, having won hearts by beating Uruguay and Italy and drawing with England in the group stage, after that it was strictly win at all costs. They drew 1-1 with Greece after extra time, winning on penalties, and 0-0 with the Netherlands after extra time, losing on penalties. The Dutch, having scored 10 times in three group games, went through a similar process.
Recent convention suggests that, even if one team want to attack in the knockout stages, their opponents will be focused on stopping them. Germany's 7-1 win stands out as an exception, facilitated by Brazil's loss of all emotional and tactical discipline. Germany's other wins en route to that final were 2-1 over Algeria (after extra time) and 1-0 over France. Four years earlier, Spain won 1-0, 1-0 and 1-0 in the knockout stages before beating the Netherlands by the same score in the final after extra time.
Denmark approached their final group game against France on Tuesday in defensive fashion, with their coach Aage Hareide declaring himself delighted with the 0-0 draw that took them through. One school of thought suggests that France, who won their group by scoring three goals in three games, should now find the freedom to express themselves but, against Messi's Argentina tomorrow, it would be a surprise if they were to open up.
Neither are Portugal, Uruguay or Russia the type of teams to go gung-ho in the later stages.
In other words, prepare yourself for a different approach once the knockout phase begins.
Gareth Southgate has hinted that he might opt for a more defensive strategy - perhaps involving Eric Dier alongside Jordan Henderson in central midfield - once the bigger, more difficult assignments come along for England.
Other coaches will be pondering the same dilemmas. The chances are that caution will increase.
THE TIMES, LONDON