And just like that, Magnus Carlsen is now the player most likely to win the Grand Chess Tour. Round 1 of London Chess Classic featured 4 draws and a win by Giri over Topalov. That made Giri jump from his initial 5.2% chance of winning London Chess Classic to 15.2%, while dropping Topalov from 10.8% to 3.1%.
Everyone else’s chances remain more or less the same, except a small drop for those who had the white pieces. However, this has a huge impact on the projected final standings for the Grand Chess Tour. Topalov’s chance is cut in half from 30% to 15%, while Giri increases his chances from 4.5% to 13.5%. Other beneficiaries of Topalov’s loss are Carlsen and Aronian, who are both dependent on Topalov placing far enough behind them if they are to win.
That is a pretty big change after just one out of 9 rounds, but it is very well illustrated by the change in Topalov’s expected final placement in London. Not only is he much less likely to win, but he is also much less likely to finish in the top 3, from almost 50% to just over 25%. Overall, his expected Grand Chess Tour point value dropped from 7.6 to 5.7. (This is the sum of each position’s point value, where you get 13 points for 1st, 10 points for 2nd, 8 for 3rd etc., multiplied with the probability of ending in that position).
Round 2 is today, and Giri is looking to cement his lead with white against the lowest rated Adams, while Topalov is looking to bounce back with white against the second-lowest rated Grischuck. Here’s this round’s probability distribution: