The player participates in an additional 10 matches. Two scenarios are considered:
Therefore, scoring 1 more goal results in an increase of the average from 0.15 to 0.20, representing a change of:
\[ 0.20 - 0.15 = 0.05 \]
This average increase of 0.05 per goal implies the following relationship:
\[ \frac{1 \text{ goal}}{x + 10 \text{ matches}} = 0.05 \Rightarrow x + 10 = \frac{1}{0.05} = 20 \]
This calculation indicates that the total number of matches played, including the additional 10, is 20.
\[ \Rightarrow x = 20 - 10 = 10 \]
The number of matches previously played is 10