The Women's World Championship Match in 6 Graphs

After starting looking like a close match in the first few rounds, Ju Wenjun went on to win 4 straight games and defended her title as Women’s World Chess Champion with a score of 6.5-2.5.
I want to give a visual recap of the match, like I did for the open World Championship match.

Expected Score after each Move

Firstly, I wanted to see how the match developed as a whole. To do this, I looked at Ju Wenjun’s expected lead after each move of the match which I calculated by adding the expected score after each move to her lead before each game.

This shows that Tan took the lead in game 2, but Ju came back immediately with a win in game 3. Tan had good chanced in the fourth game but after that Ju won games 5 through 8 and with that the match. It can also be seen that Ju’s conversions in games 5 and 6 weren’t perfect.

Quality of Play

While the expected score after each move gives some indication of the quality of play, I wanted to see a more detailed breakdown of the accuracy. Below is the distribution of the move accuracies for both players which shows the relative number of moves played at each accuracy.

It’s interesting to see that Ju is the only player who made some big mistakes, which can also be seen in the expected lead graph in games 2 and 6. However, Tan made more moves with an accuracy from 50 to 80 which lead to Ju’s convincing victory.
Another way to get a feeling for how the match went is to look at the times where each player had a good or bad position.

This graph shows the relative number of moves where Ju was much better (evaluation greater than +1), better (evaluation between +1 and +0.5), equal (evaluation between +0.5 and -0.5), worse and much worse during the match.
Most of Ju’s victories came from long endgame grinds and so she was much better for roughly 70% of the moves during the match.

The conversion of chances is also very important in matches. To see how well the players used their chances, I looked at the number of games where player was better and how many games they actually won.

Ju used all the chances she got in the match and at the same time didn’t offer much to Tan which lead to the dominating result.

Sharpness

The players also differ in style, with Ju being more solid and Tan more tactical. This can be seen in the average sharpnesschange on each move.

Ju’s sharpness change in the opening is mostly negative, meaning that she tried to keep the game calm. The picture becomes more messy after move 10 as the players go for specific lines given the position on the board and not general match considerations.

Clock Times

While watching the match, I noticed that Tan usually played very quickly and this can also be seen from the average clock times.

The clock times would suggest that Tan was better prepared as she played more moves without thinking much in the opening. Her time advantage increased on average over the course of the games but she wasn’t able to use that to score points.

Conclusion

Looking at the quality of play and the final score shows that these two things don’t necessarily go hand in hand. Tan played well for most of the games but didn’t find the right moves in some important situations which lead to a clear win for Ju.
Let me know what you think of this recap and if there are some other stats about a match you’d like to see in the future.

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