## Saturday, 6 December 2014

### Using Weighted Shots To Predict Goal Difference in Subsequent Games.

As a follow up to the previous post, here is the changing relationship between a side's weighted shot differential compared to their opponents, for goals, shots that went wide and shots that were saved after a certain number of matches and the goal difference in the remainder, as suggested in the comments by Tango.

The EPL has 38 games,

So, for example, the projection for the goal difference in games 3 to 38 inclusive is found by multiplying the oerall GD in games 1 and 2 by 2.9, adding the differential of shots that went wide after two games multiplied by 0.43 and adding the save differential after two games multiplied by 1.24. The constant is universally close to zero.

r for each regression after each number of games is in the final column and peaks at mid season.

Correlation Between Shot Type Differential in Previous Games & Goal Difference in Remaining Games.

 After x Games Goal Difference  Coefficient Shots Wide Differential Coefficient Shots Saved Differential  Coefficient Relative Weight for GD Relative Weight for Wide Shots Relative Weight for Saved Shots r 2 2.9 0.43 1.24 1 0.1 0.4 0.57 3 2.5 0.59 0.92 1 0.2 0.4 0.67 4 2.3 0.40 0.71 1 0.2 0.3 0.72 5 1.9 0.38 0.57 1 0.2 0.3 0.76 6 1.8 0.33 0.45 1 0.2 0.3 0.77 7 1.6 0.25 0.37 1 0.2 0.2 0.79 8 1.4 0.24 0.30 1 0.2 0.2 0.79 9 1.2 0.22 0.27 1 0.2 0.2 0.76 10 1.1 0.17 0.24 1 0.2 0.2 0.76 11 1.05 0.15 0.19 1 0.1 0.2 0.77 12 .99 0.15 0.16 1 0.1 0.2 0.78 13 .91 0.13 0.14 1 0.1 0.2 0.81 14 .82 0.11 0.14 1 0.1 0.2 0.81 15 .75 0.09 0.14 1 0.1 0.2 0.80 16 .72 0.09 0.12 1 0.1 0.2 0.81 17 .6 0.06 0.14 1 0.1 0.2 0.81 18 .55 0.02 0.15 1 0 0.3 0.80 19 .46 0.02 0.14 1 0 0.3 0.78 20 .43 0.01 0.13 1 0 0.3 0.79 21 .39 0.01 0.12 1 0 0.3 0.78 22 .36 0.01 0.10 1 0 0.3 0.79 23 .31 0 0.09 1 0 0.3 0.76 24 .28 0 0.09 1 0 0.3 0.77 25 .25 0.01 0.08 1 0 0.3 0.75 26 .20 0.01 0.08 1 0 0.4 0.74 27 .17 0.01 0.07 1 0 0.4 0.72 28 .15 0 0.07 1 0 0.4 0.70 29 .13 0.01 0.05 1 0.1 0.4 0.69 30 .13 0.01 0.04 1 0.1 0.3 0.69 31 .11 0.01 0.03 1 0.1 0.3 0.66 32 .08 0.01 0.03 1 0.1 0.3 0.64 33 .06 0.01 0.02 1 0.2 0.4 0.60 34 .05 0.01 0.02 1 0.1 0.5 0.56 35 .04 0 0.02 1 0 0.5 0.48 36 .02 0 0.02 1 0 0.7 0.40 37 .02 0 0 1 0 0.2 0.32

#### 1 comment:

1. Hi, I think it will be useful to do the analysis on a per-game basis. Meaning shots difference/game etc.