Is the stuttering penalty kick losing its effectiveness?

Whether or not France's World Cup campaign ends with a third world title, few will remember Kylian Mbappe's penalty miss in their quarter-final victory over Morocco.

The match in Foxborough was goalless when Mbappe was fouled by Noussair Mazraoui. The France captain stuttered in his run up, looked up at goalkeeper Yassine Bounou, and saw his tame penalty easily saved.

Mbappe made amends on the hour mark when his sensational curling effort broke a stubborn Morocco defence, before Ousmane Dembele doubled France's lead six minutes later to secure a 2-0 win.

But his earlier blunder, uncharacteristic for the joint-top scorer in this tournament, begs the question: Is it time players stopped with the 'stuttering' penalty kicks?

In the list of things football traditionalists hate about the modern game, stuttering run ups are high up alongside players wearing gloves with short sleeve shirts, diving, and of course the video assistant referee (VAR).

There is no strict definition of a stutter, but under Fifa rules, a player is allowed to stop or feint during the run-up as long as they don't do it directly before kicking the ball.

It's nothing new - John Aldridge, Mexico legend Hugo Sanchez and Pele all used the stutter to gain an advantage - but it can backfire spectacularly if the goalkeeper doesn't commit to diving early.

Mbappe joins Bruno Guimaraes, Jorgen Strand Larsen, Lionel Messi and Harry Kane (though he was able to retake his penalty against Croatia, which he scored without having a stutter in his approach) in missing penalties after stuttering in the run-up.

Of the 26 'stutter' penalties taken during this World Cup - penalty shootouts included - 11 have not been scored, which leads to a conversion rate of 57%.

"This stuttering penalty seems to be the one. The goalkeepers seem to have got a march on it now," said Ian Wright on ITV.

Marko Arnautovic, Raul Jimenez, Neymar, Mbappe, Cristiano Ronaldo, Yoane Wissa and Kai Havertz have used the technique successfully.

Meanwhile, 24 of the 35 'non-stutter' penalties taken have been scored, a conversion rate of 68%.

In general, this has been a poor World Cup for players looking to convert from 12 yards.

A total of 30% of non-shootout penalties have been missed this summer, the second most of any World Cup since records began in 1966.

When shootout penalties are added to the equation, then the miss rate rises to 35%, the highest of any World Cup since 1966.

"There is an arms race going on. It is definitely harder to score a penalty now. The reason being, the goalkeepers are bigger now, more athletic," former Scotland winger Pat Nevin said on BBC Radio 5 Live.

"If your keeper goes the right way, you must hit the side netting with pace, even then it still might be saved.

"A very good penalty is no longer a certainty, so you have to re-think it. I need to make sure he goes the wrong way, hence the stutter, you try to send them the wrong way.

"Of course the goalkeepers have the data, they know what everybody does, there is no hiding what you prefer because it shows up. There is a constant running battle to figure out how you get the advantage.

"Mbappe knows what his advantage is: preparation. He has a set up [placing the ball before taking the penalty], he went through it twice today but problem is that he had to go through it three times, and the third time [he missed]."