When evaluating goalkeepers, it’s not enough to just count how many saves they make. We need to understand the quality of the shots they face. 

This is where Expected Goals on Target (xGOT) becomes a powerful tool. By using xGOT, we can measure how well a goalkeeper performs, especially when dealing with difficult shots. 

One key metric that helps us do this is Goals Prevented, which shows how many goals a goalkeeper has prevented based on the quality of shots they’ve faced.

1. What is xGOT for Goalkeepers?

xGOT measures the likelihood of a shot becoming a goal after it’s taken. For goalkeepers, xGOT helps us see how difficult the shots they face are. 

A shot with a high xGOT value means it’s a tough shot to stop, while a low xGOT means it’s easier to save.

2. Calculating Goals Prevented

We can use xGOT to calculate Goals Prevented, which tells us how well a goalkeeper is performing compared to what we would expect based on the quality of shots they face.

• Goals Prevented = xGOT conceded – Goals conceded

This formula helps us measure whether a goalkeeper is saving more or fewer goals than expected.

If Goals Prevented is positive: The goalkeeper is doing better than expected, saving difficult shots that most would expect to result in goals.

If Goals Prevented is negative: The goalkeeper is underperforming, letting in goals that they should have saved based on the quality of the shots.

3. Why is This Important?

Using Goals Prevented helps us identify which goalkeepers are truly performing well. A high number of saves doesn’t always mean a goalkeeper is great—they might just be facing easy, low-quality shots. 

By using xGOT, we can see which goalkeepers are making important, high-quality saves and who might be struggling against tougher shots.

4. Example of Measuring Goalkeeper Performance

Let’s say a goalkeeper faces shots with a total xGOT of 10.0, meaning the shots they’ve faced are expected to result in 10 goals. However, the goalkeeper only concedes 7 goals.

• Goals Prevented = 10.0 (xGOT) – 7 (goals conceded) = +3.0

This means the goalkeeper has prevented 3 extra goals through high-quality saves, showing they are performing above expectations.

Conclusion

Using xGOT to measure Goals Prevented is a valuable way to analyze goalkeeper performance. It allows us to see how well goalkeepers are doing based on the difficulty of the shots they face, rather than just counting their saves. 

This metric helps distinguish between goalkeepers who are making top-quality saves and those whose save totals are inflated by easier shots.