TATA Steel Chess is Really Close

After 6 rounds of TATA Steel Chess three players are tied at 4 points. We have been running a model to predict the outcome and publishing over on our twitter feed, and as we approach the half-way stage it is a really close race to win it. Now this might not be very surprising given that there is a three-way tie, yet the way our model claims it is close might be a bit more surprising. Here are the model’s prediction after 6 rounds:

160123 Win Chances R6

Each player’s chance of winning TATA Steel Chess after 6 rounds.

Magnus Carlsen has the best chance, followed by tie-break and then Fabiano Caruana. Surprisingly, the third player currently tied for first is given only a 10% chance of winning by our model. To investigate why this is the case, let us first start with some background of how our model works.

Our model is based primarily on each player’s live-rating, where the player with the white pieces are given an increased rating to correspond with white’s advantage. We use chess-db.com’s calculations of draw rates to calculate the chances of a draw in each game, then use ELO-math to calculate probable outcomes of each game. Then the model simulates each game 10 000 times that we then use for the remaining calculations.

So let us first look at why Ding is “only” given a 10% chance of winning the tournament. The answer is simply Black against “The Cars”. In round 7 he has black against Caruana (where he has a 31% chance of losing), and in the final round he has black against Carlsen (40% chance of losing). Combined with the fact that he has a much lower rating than the two, his overall chances are pretty slim compared to his position right now.

But why is Carlsen only a slight favorite to win, with a lower chance now than before the tournament started (31%)? Starting from the premise that his live rating is 49 points higher than Caruana, one would think his chances were greater than the model says. Well, the very first thing that influences this is that Caruana has 4 games with white remaining, while Carlsen only has 3. Advantage Caruana. And perhaps more important, Caruana’s remaining opponents are rated much lower than Carlsen’s. The remaining opponents of Caruana have an average rating of 2726, which gives him the easiest schedule of all the remaining players. Carlsen, on the other hand, faces players with an average rating of 2755. That puts him at number 4 of who has the toughest schedule (behind Adams, Karjakin and Eljanov, who all has to play the World Champion). Basically, Carlsen’s plays his remaining games against the world’s 14th best player, while Caruana plays the 27th.

And overall, the easier schedule and an extra game of white is almost enough for Caruana to counter Carlsen’s superior rating. In fact, their expected points distribution is more or less an overlap, with a slight edge for Carlsen.

160123 Expected points The Cars R6

The expected points distribution for The Cars (Carlsen and Caruana) after R6 of TATA Steel.

On average, with 10 000 simulations, Magnus Carlsen scores 8.31 points, while Fabiano Caruana scores 8.22. That’s close!

We’ll end this post with an overview of each player’s expected points distribution, including their average points.

160123 Expected points distribution R6

Expected points distribution of TATA Steel Chess after Round 6. The average score in parenthesis, and the blue dot represents the most likely amount of points each player gets.

This entry was posted in Chess, Models and tagged , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s