Win Chances of Grenke Chess Classic After Round 5

Magnus Carlsen won again, and is now tied with Arkadij Naiditsch for the lead in the Grenke Chess Classic (although he would be ahead on tie-break at the moment). Levon Aronian also won his game, pushing Viswanathan Anand out of the running for the title. According to the model, Carlsen is now back as the favorite to win it all. Listed below is the current win chances of the tournament, with the original chances outlined in blue and the win chance after the previous round in yellow.

Probability distribution of win chances following the fifth round.

Probability distribution of win chances following the fifth round.

Both Naiditsch and Caruana lost a bit of ground to Carlsen with their draw, and even with his win Aronian did not really improve his chances. His chances are pretty much dependent on him winning his remaining games, and hoping other results go his way. It still looks like a race between Carlsen, Naiditsch and Caruana, with Caruana needing a good result against Carlsen in Round 6. More on that game later.

Here are the expected averages:

Player Mean Median Mode
Carlsen 4,62 4,5 4,5
Naiditsch 4,49 4,5 4,5
Caruana 4,07 4 4
Aronian 3,52 3,5 3,5
Adams 3,46 3,5 3,5
Bacrot 3,42 3,5 3,5
Anand 2,60 2,5 2,5
Baramidze 1,82 2 1,5

For Naiditsch, this is exactly the same as it was after Round 4, while Carlsen improved. Aronian has also improved a lot and is expected to score slightly better than Adams and Bacrot. This is also reflected in the expected points distribution.

Each player's distribution of expected points following Round 5.

Each player’s distribution of expected points following Round 5.

So why is Aronian’s win chance lower than Bacrot’s when he’s expected to score better? Because Bacrot’s last two games are against Naiditsch and Carlsen, and if he wins those he has a good chance of winning it all. Aronian on the other hand plays Adams and Naiditsch, and even if he wins both those games Carlsen and/or Caruana can still match him and win.

The model expects Carlsen to place either first or second in the tournament 86% of the time, thus continuing his streak. He is expected to win outright 35% of the time, be in a tie-break 28% of the time, while placing second 23% of the time.

The games in Round 6 can be pretty decisive, and here are the model’s predictions:

White Black White wins Draw Black wins
Anand Baramidze 37.1 % 47.9 % 15.0 %
Caruana Carlsen 23.9 % 51.5 % 24.6 %
Bacrot Naiditsch 30.4 % 46.3 % 23.3 %
Aronian Adams 27.0 % 56.1 % 16.9 %

As stated earlier, let’s focus a bit on the game between Caruana and Carlsen. Caruana is the number 2 player in the world and playing with white, yet the model slightly favors Carlsen in the game. That must be wrong, right? Well, not necessarily. Caruana may be number two, but Carlsen is by far number one. In fact, he is rated 54 points higher than Caruana. That computes to his expected score against Caruana being 0.577. So in order for Caruana to cancel this advantage, it means that the effect of playing white should be the same. If we say for sake of argument that the chance of a draw is 50%, that means white should win 32.7% of the time and black 17.3% of the time to cancel the effect of Carlsen’s superior rating. Most data on first-move advantage puts white’s expected score at 0.55, which is somewhat lower than what Caruana needs in order to be favored.

But this is just math, we will see what happens when the player’s face each other in Round 6.

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2 Responses to Win Chances of Grenke Chess Classic After Round 5

  1. Pingback: Predicting the Grenke Chess Classic | Analytic Minds

  2. Pingback: Win Chances of Grenke Chess Classic After Round 6 | Analytic Minds

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