How to take a penalty, and how to save one? With the World Cup’s knockout stages starting on Saturday, these questions could decide who wins the trophy. At the 2018 tournament, four games in the knockout rounds were tied after 120 minutes and won on penalty shoot-outs. This time, some teams have prepared better than ever. Others have not.   

The first thing to know is how your opponents shoot. Broadly, every kicker has to answer one question: do you wait until the keeper moves? Croatia’s Luka Modri? does. He runs up slowly, head raised, watching the keeper for the slightest indication — even a lifted heel — of which way he’ll move. At that cue, Modri? taps the ball the other way. He has converted 21 of his 24 career penalties, or 88 per cent, according to Transfermarkt. The football-wide conversion rate has dropped over the past decade from 82 per cent to about 75 per cent, probably because data analysis helps teams decrypt opposing kickers.

A keeper facing Modri? — or Poland’s Robert Lewandowski — will want to stay immobile as long as possible. That worked for Uruguay’s Sergio Rochet against Ghana on Friday: unfooled by André Ayew’s slow approach, he chose the right corner, helping send Uruguay through to the knockouts at the Ghanaians’ expense.