Sprint back at the carrier and you lose; sprint back past him and the counter dies without a tackle.
The best recovery run never touches the ball
Watch the second defender. Not the one chasing the ball, the one running a line that looks, for about four seconds, completely pointless.
A counter-attack is a race with a strange finish line. The naive recovery run treats the ball carrier as the target, which means the defender arrives at the carrier's shoulder, slightly behind, slightly off balance, and has three options, all bad. He can dive in from behind and give a free kick in a dangerous area. He can run alongside and hope. Or he can slow down and start backing off, at which point he has spent all that energy to become a passive obstacle.
The useful run ignores the carrier entirely. It aims at the space the carrier wants to pass into, usually the inside channel where the second runner is arriving, and it gets there first. Now the carrier is holding a ball with no forward pass. He has to take a touch, and a touch is a tenth of a second, and a tenth of a second is enough for four other people to get behind the ball.
There is a reason this run is undervalued: it produces no event. No tackle, no interception, no clearance, nothing that appears in a match log. A player who does it five times in a game shows up in the data as somebody who did nothing except cover ground, which is the least respected number in football.
I think that is why so many attacking full backs are described as poor defenders when the real problem is a coaching one. They are being asked to sprint eighty metres and then defend a one against one at the end of it, which nobody can do. Ask them instead to sprint eighty metres and cut a passing line, and the same player looks disciplined.
Angle beats speed here more often than people admit. A slower defender who leaves on the right line arrives ahead of a quicker one who leaves at the ball. You can see it in any transition sequence if you stop watching the ball for ten seconds, which is admittedly hard, because the ball is where the interesting thing appears to be happening.
The best recovery runs end with a striker turning back towards his own goal. Nothing happened. That was the point.

