Speed of Attacks

Measuring speed is easy, it's just distance travelled/time. Right?

But that's not really the correct approach to take on a football pitch.

Making 30 yards running from deep in 5 seconds probably isn't the equivalent of making the same, but with the halfway line as the starting point.

In Non Shot expected goals terms you're going from a very small threat to a slightly greater threat in scenario one and from a moderate threat to a really dangerous threat in the second case.

So instead of using distance made/time to measure the speed of an attack, we measure Non shot xG gained/time to define the speed of an attack in football.

It even comes out as a sensible double digit number if you convert it to NSxG per hour!