My first expected goals studies, published at SB Nation.
Shot Matrix I: Shot Location:
Shots from outside the box kind of suck. If you really do have a shooting lane to put the ball on target, they’re not necessarily the worst, but a huge percentage of shots from outside the box result in turnovers, either goal kicks or blocked shots that can produce transition opportunities. The cost of shots from outside the box comes in those 75% of instances when the keeper is not called into action at all.
Shot Matrix II: Headers and Crosses:
Once you get outside of the six-yard box, chances off crosses and headers lose a lot of their value. I like how the numbers on headers off crosses and other headers converge to an 8% conversion rate by quite different means. Hitting a cross ball with your head from twenty feet or more and putting on target is very difficult. If you do get it on target, there’s at least a non-terrible chance that you got enough power and precision behind the ball to score. On other headers, where the ball is most likely coming in at a kinder speed and angle, directing it to goal is relatively easy. Beating the keeper, though, is incredibly difficult as you rarely get enough power on the header to trouble the keeper.
Shot Matrix III: The Incredible Through-Ball:
I have a total of 1738 shots off through-balls logged in my database. A negligible number come from either outside the box or from Zone 1. No professional keeper would stand rooted to his line as a pass split his defense which allowed an attacker to run onto the ball in the center of the six-yard box. I presume that the 12 shots off through-balls from Zone 1 in my database represent shots where the attacking player collected the ball further from goal, rounded the keeper, and then finding himself in front of goal, took the shot.