# The GWS En Primeur Price Tool

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We are excited to announce the release of our en primeur tool that makes it easy to compare the price of Bordeaux wines with their Global Wine Score to find great values during the en primeur campaign.

To access the tool, just sign into your GlobalWineScore.com account (it’s free to sign up) and go to the Primeurs page. Then you can select the vintage, color, and style of wine you want to compare. You can narrow your selection further by appellation and classification, or you can create your own custom list. The result is a chart and table showing the trend of scores and prices for your selected wines. For a more detailed explanation of how to use the tool, you can view our tutorial video.

Now, let’s take a closer look at the mathematics behind the tool.

# Global Wine Score vs. Price: A Regression Analysis

In order to look at the relationship between scores and prices, our team of data scientists and statisticians used a regression analysis to determine how price is affected by score. The relationship between score and price is usually exponential, which means that on the high end of the score range, each point increase in score is coupled with a proportionately larger increase in price. This explains why the price difference between a 95-point wine and a 90-point wine is generally much larger than the price difference between a 90-point wine and an 85-point wine.

In order to show each data point clearly on a single chart, we use a logarithmic scale on the Y-axis for price. As you can see in the chart above, the scale jumps from 1 to 10 and then from 10 to 100 in the same distance. The logarithmic scale allows us to present the regression line, or the trend line, as linear. When looking at the regression line, the distance of each point from the line is comparable across the entire chart. This makes it easy to compare the relative value of wines just by looking at the chart.

# Find Great Values During En Primeur

Now that we have reviewed the mathematics behind the tool, let’s discuss how we can use the tool to find great value wines. Any wine that lies below the regression line has a lower than average price given its score, and the reverse is true for wines that lie above the line.

The distance of a data point from the line is measured by what we call the residual. You can view the residual value for each wine by hovering over the data point on the graph or by looking at the table. In the table below, you can see the wine’s price per bottle, Global Wine Score, residual (R), and Price-Quality Rating (Q€). The best value wines have the lowest residual value and the degree of value is rated from + to +++ for the best values.

Now you are ready to try the tool yourself! The tool is updated daily with the latest 2017 release prices, and the tool has price and score data going back to the 1995 vintage. We hope you enjoy using the en primeur tool!