Thread by @Jhdharrison1

A GK’s handling ability is vital & often under analysed!

Here #DeGea showed how handling can determine a game’s outcome when he parried a 49mph central shot into danger & the rebound was scored!

xRebound xG = 0.09
Actual Rebound xG = 0.47

xG added due to poor handling = 0.38

My handling model uses historic shot data to gauge how often certain shots should be expected to be caught, parried away from danger, & parried into danger in combination with a none shot xG model which assesses how likely rebounds are to be scored based on the parry location

My model found that due the shot’s lower than avg velocity & central trajectory an avg PL GK would expect to parry the ball into an area which resulted in a goal from the rebound only 9% of the time whereas #DeGea pushed it into an area which results in a goal 47% of the time!

As an example:

Catches are perfect & goals result in rebounds from them 0% of the time whereas parrying it out for a corner results in a goal ~3% of the time (as ~3% of corners are scored) & parrying it straight back to 6yrds out centrally results in a goal ~75% of the time.

So in the super simplified case above if a shot was expected to be caught 50% of the time, parried out for a corner 40% of the time & parried back centrally 10% of the time the xRebound xG would be 0.087 ie would result in a rebound which results in a goal 9% of the time.

#DeGea’s handling was pretty bang average for a #PremierLeague GK last year

But interestingly the majority of his bad parries occurred in 2 ways:

Shots from out wide which go centrally (like the #March one) & close range headers

Hinting this is a recurring weakness in his game

Lots of people are commenting that #Sanchez’s handling during the game was far worse & he got lucky that the #BHAFC defenders bailed him out & those people would be 100% correct!

#DeGea’s handling score for the game was -0.38xG while #Sanchez’s was -0.65xG!

This is exactly why I hate metrics like errors leading to goals!

Just because a goal or rebound doesn’t happen doesn’t mean it is a good parry

My handling model nicely shows that both #DeGea & #Sanchez had poor handling at the weekend even though only #DeGea conceded a rebound!