Defend as a connected unit. Slide across together with the ball, keep 6 to 8 metres between each defender, press with the nearest player while the rest cover and balance, and stay compact to force the play wide.
Attackers pass the ball across the top of a grid; the back four slides across to stay in front of it. The nearest defender presses the ball, the others tuck in and cover behind. Keep the line straight and the distances tight, and read the pass that tries to split the line. Use clear calls: Step, Drop, Slide, Hold. Progress to a live small-sided game.
Six to eight metres between defenders is the working range for a back four, and both ways of getting it wrong show up immediately. Too tight and the line covers a narrow strip while the pitch is open outside it, which is why compact teams get switched on. Too spread and any pass between two defenders splits them, because neither can reach the ball or cover the other.
What makes the number hold is that the line slides as one. The cue is the pressing defender: whoever is nearest the ball goes, and the other three shift relative to him rather than relative to the ball itself. Defenders who take their reference from the ball end up at different distances and the spacing breaks down within two passes.
The division of labour inside the four is standard and worth naming. The nearest presses. The next covers behind and inside him. The far two balance, which means tucking in rather than marking their own direct opponents. The far full-back tucking in is the instruction defenders resist most, because he can see an unmarked winger on his own touchline and it feels like negligence. Explaining that the switch takes three seconds to arrive, and that he has that long to travel, is what makes it stick.
Forcing play wide is the objective rather than winning the ball. A back four that funnels everything into wide areas and defends crosses is doing its job, and judging the unit on turnovers rather than on where the opponent ends up teaches the wrong instinct.
Save it to your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block. Or start from a blank pitch and build your own.