Yeah. A football pitch is really big.

Wouldn’t it be cool if the team trying to defend all that space could just, like… chop it in half?

That’s exactly what Arsenal tried to do against Spurs.

It’s often said that a presser who closes down the ball from one side has “cut the pitch in half” because the player on the ball has no choice but to pass in the other direction. The nearer the presser can get to the ball, the more space they block off behind them (in the inaccessible area known as their “cover shadow”). And if they come at the ball sideways, the area they block off will all be on one side of the pitch.

Typically, this happens when the ball is with the goalkeeper and there’s no option to play backwards. Throw in an offside trap somewhere around the halfway line and a high press that succeeds in cutting the pitch in half really only has to contest the ball in a quarter of it — still a few basketball courts’ worth of grass, but not a job that will take 11 Giannis Antetokounmpo-level freaks to cover.

Here’s what it looks like when it works:

Arsenal’s pressing scheme here involves two players up top defending zonally (meaning they mostly stay in one spot) about 10 to 15 yards in front of the Tottenham center-backs, while the next four players behind them do a bunch of man-marking in midfield (meaning they chase guys around).

The man-markers’ job is to deny midfield passing options long enough that goalkeeper Guglielmo Vicario will roll the ball sideways to one of those centre-backs.

When Vicario delivers it to centre-back Micky van de Ven, Martin Odegaard, the zonal player in front of the centre-back, creeps forward to make him turn around to pass back to the goalkeeper again. That moment of vulnerability when Van de Ven turns his back is Odegaard’s pressing trigger — it’s time for him to spring forward to close down the ball while his team-mates seal off nearby passing options.

Odegaard doesn’t run straight at the ’keeper. He curves his pressing run, first heading toward Van de Ven and then following the ball back to Vicario at an angle that blocks any return pass. With no good passing options on that side and Odegaard coming in hot, Vicario turns to his right, away from pressure.

This turn protects the ball for a moment, but it also forces his hand: the next pass will have to go to the other side of the pitch.

Arsenal have cut the pitch in half.

Like all football tactics, this one isn’t airtight.

The angle of Odegaard’s pressure hasn’t actually zapped Van de Ven into some forbidden dimension.

If Tottenham can get the ball back around to his side with a third-man combination through a dropping midfielder, Van de Ven will be free behind Odegaard on the supposedly blocked-off side of the pitch. The press will be “broken”, meaning the build-up has found a free man behind the pressure and can attack in space while the defense scrambles to recover its shape.

But to get there, they will have to work the ball through the compressed playing area between Odegaard’s cover shadow and Arsenal’s offside trap. There are only three nearby passing options for Vicario on that side and two of them are covered.

The cautious thing would be for him to send it long, but Tottenham don’t want to do that. They’re a little crazy, remember? They want to play short into that open space behind Odegaard.

Anyway, you know how it turns out. James Maddison drops all the way into his penalty area to make the third-man relay pass. Declan Rice isn’t sure he should let his man drag him that far forward, so he calls for Gabriel Jesus to switch onto Maddison. Jesus charges forward, bodies Maddison off the ball and fires in a shot that very nearly puts Arsenal 2-0 up.

Cutting the pitch in half has produced one of the best chances of the game.

The cool thing about good pressing is that it isn’t limited to big clubs such as Arsenal. The tiny Canary Islands outfit Las Palmas, whose promoted squad ranks dead last in La Liga by Transfermarkt value, currently has the sixth-best defence in Spain’s top division by non-penalty expected goals per game, one place ahead of champions Barcelona.

How are they punching above their weight? They don’t have the quality to win defensive duels in open space, but they do have the discipline to cut pitches in half.

Here’s an example of how they did it against visitors Granada last weekend:

Games like this, between two smaller clubs, tend to feature less of the controlled-build-up-versus-press battle than a heavyweight bout such as the north London derby, but pressing principles still apply.

Like Odegaard in the example above, Las Palmas forward Munir El Haddadi forces a centre-back to turn back to goal and then makes a curved pressing run to cut off the lane between him and the goalkeeper. When they see Munir trigger the high press, two of his team-mates sprint forward to close down midfield passing options on the open side of the pitch.

Granada goalkeeper Andre Ferreira makes what looks like a safe choice: a chipped pass to an open full-back on the sideline. But Las Palmas left-back Sergi Cardona, seeing Ferreira has only one passing option, is already sprinting that way. He steps in front of the pass and wins the header, leading to a dangerous chance for Las Palmas.

That defensive read isn’t possible without Munir’s sideways pressure to seal off half the pitch.

As simple as pressing from the side sounds, it’s not easy to trap the goalkeeper on the ball in a lot of space. El Haddadi, known as Munir, is particularly good at subtly varying his angle, speed and direction in clever ways to close the distance without allowing a press-breaking pass around him, as in this other, similar sequence against Granada:

(If you doubt how important those few degrees between blocking a passing lane and allowing the press to be broken are to coaches, remember that Gareth Southgate has cited pressing angles as the reason Phil Foden can’t get into his England midfield: “In the middle of the park, everybody wants to talk about them (players) with the ball, but there’s a lot of detail without the ball. You’re playing opponents that are so clever with their passing and movement that you’ve really got to be spot-on with pressing angles, your responsibilities.”)

Even when the lead presser takes a good angle and succeeds in closing down the goalkeeper, cutting the pitch in half only works if their team-mates join the press.

Late in the first half of the north London derby, Eddie Nketiah chased a ball back to Vicario before Arsenal’s midfield got organized behind him. With nobody in position to mark him, Spurs midfielder Yves Bissouma was able to make an easy third-man relay to Cristian Romero behind Nketiah, breaking the press.

Arsenal never recovered.

This time, Maddison drops to the ball and Rice isn’t sure whether to follow or call for a switch, leaving Maddison in space to send a ball up the wing, leading to a Tottenham goal: