Tblisi Grand Prix – Second Rest Day Update

While our top story from the first rest day (the rise of Tomashevsky) has continued unabated, there is now a second key story line at play in this event: the fall of Grischuk. While Tomashevsky scored 2.5/4 and maintained his full point lead over the field, Grischuk dropped two games, scored only 1/4, and fell firmly out of contention. In this post we will be examining the deeper ramifications (both obvious and subtle) of these two players’ results, as everything else depends on them.

First the obvious: Tomashevsky’s position has improved greatly. While his lead hasn’t actually grown, it should be obvious that a full point lead over just one player, with only three games left, is a far stronger advantage than a full point lead over three different players, with seven games left. Evgeny didn’t particularly need to extend his lead, merely hold serve as others fell off the pace. In this case it was Grischuk and Giri who dropped further behind, while noone else closed the gap. How much better is Tomashevsky looking at this point, than before? In the last four rounds his odds of winning the event outright have improved from 31% to a whopping 79%! His expected score (in Grand Prix Points) is now 164 – keeping in mind that you score 170 for a clear first, and just 140 for second. Even the one time in five that he doesn’t win outright, he will almost always share first, usually with only one other player, and still bring home 155 points. His odds in the overall Grand Prix standings, meanwhile, are now up to a 42% chance of finishing top two (and qualifying for the Candidates Tournament). This is a humongous gain over his round four position, when despite his great start he had just a 17% chance, or especially over his pre-tournament odds when we evaluated him as having only a 2% chance of being a Candidate for the World Championship next year.

Here are average expected points scored at Tbilisi, and odds of winning first place outright, for all players. You may notice that it isn’t much of a race at this point.

Player Score (Out of 8) Tbilisi EV Odds of Clear 1st
 Evgeny Tomashevsky (RUS) 6 164 79%
SHARED FIRST 15%
 Dmitry Jakovenko (RUS) 5 124 5%
 Rustam Kasimdzhanov (UZB) 4.5 89 1%
 Teimour Radjabov (AZE) 4.5 87 1%
 Anish Giri (NED) 4 77 0%
 Shakhriyar Mamedyarov (AZE) 4 72 0%
 Baadur Jobava (GEO) 4 65 0%
 Leinier Dominguez (CUB) 4 57 0%
 Alexander Grischuk (RUS) 3.5 59 0%
 Maxime Vachier-Lagrave (FRA) 3 32 0%
 Peter Svidler (RUS) 3 26 0%
 Dmitry Andreikin (RUS) 2.5 20 0%

While it has little bearing on the overall Grand Prix standings, or even on the results at Tbilisi, we would like to highlight how impressively Jobava has bounced back from an atrocious start. After managing just one draw and three losses in the first four rounds, he has won three and drawn one in his last four rounds, returning to an even 50% score for the event, and bringing his live rating back above 2700.

Grischuk, on the other hand, has fared most poorly over the past four days. As the highest rated player in the field, he was expected to score well more often than not, so after round four we saw him as the most likely contender to potentially chase and catch Tomashevsky. Instead he tumbled. Where before we expected him to score an average of 113 Grand Prix Points, now we see him picking up only 59, which would not keep him alive in the overall Grand Prix standings. By virtue of his rating, he remains one of the favorites in the final event at Khanty-Mansiysk, but at this point his overall odds of reaching the Candidates Tournament via the Grand Prix are just 12%, whereas four games ago we had him at 41%. If he is going to get there, it will have to start over the final three rounds of Tbilisi. He has no realistic hope of winning this event, but if he can win a game or two and rise in the standings, it would gain him critical extra Grand Prix points that would keep him at least somewhat in contention overall, and keep his results relevant at Khanty-Mansiysk.

Here is where all 16 players in the Grand Prix stand, for average final score expectations, as well as odds of actually reaching the Candidates Tournament:

Player Baku Tashkent Tbilisi EV Khanty-Mansiysk EV TOTAL EV Top-Two Odds
 Fabiano Caruana (ITA) 155 75 100.9 330.9 68%
 Evgeny Tomashevsky (RUS) 82 164.4 60.7 307.1 42%
 Hikaru Nakamura (USA) 82 125 97.6 304.6 49%
 Alexander Grischuk (RUS) 82 59.0 97.3 238.3 12%
 Boris Gelfand (ISR) 155 15 64.1 234.1 8%
 Shakhriyar Mamedyarov (AZE) 35 125 72.0 232.0 1%
 Sergey Karjakin (RUS) 82 75 70.6 227.6 7%
 Dmitry Jakovenko (RUS) 30 123.7 62.0 215.7 5%
 Anish Giri (NED) 40 76.7 93.8 210.5 5%
 Dmitry Andreikin (RUS) 20 170 19.9 209.9 0%
 Teimour Radjabov (AZE) 50 50 86.8 186.8 0.05%
 Baadur Jobava (GEO) 75 64.7 41.2 180.9 1%
 Maxime Vachier-Lagrave (FRA) 75 31.7 74.0 180.7 1%
 Peter Svidler (RUS) 82 25.7 54.0 161.6 0.4%
 Rustam Kasimdzhanov (UZB) 35 15 88.8 138.8 0%
 Leinier Dominguez (CUB) 10 56.8 53.8 120.5 0.03%

You may notice, from the numbers above, two other major beneficiaries of Grishcuk’s collapse: Hikaru Nakamura and Fabiano Caruana. While sitting on the sidelines, these two have seen their chances improve significantly over the past four rounds, improving eight percentage points each over where they stood at the first rest day. Why? As the leaders in the overall Grand Prix standings prior to this event, they were in the best position to benefit from the rise of a relatively weak favorite at Tbilisi. While we don’t wish to take anything away from how impressive Tomashevsky has been at this event, he is still rated 50-60 ELO lower than the top rated players in the Grand Prix, and so our model projects him as less likely to repeat his success at Khanty-Mansiysk than, say, Grischuk or Giri would have been. So having more of Tbilisi’s Grand Prix points likely to be awarded to lower rated players puts Caruana and Nakamura in much better positions to maintain their leads through the final leg of the Grand Prix.

Also working in the leader’s favor has been the disappointing results for two other higher rated players: Giri and Vachier-Lagrave. While they never had as much hope originally as Grischuk did, making their drops less dramatic, they nevertheless have seen their odds of qualifying for the Candidates Tournament drop precipitously over the course of this event. Just like with Grischuk, these other drops from high rated players have also benefited Nakamura and Caruana… as well as helping Tomashevsky greatly, of course. Here is how each of the 16 players in the Grand Prix field has trended from before Tbilisi started, to the first rest day, to the second:

Player ODDS (PRE-TBILISI) ODDS (TBILISI REST 1) ODDS (TBILISI REST 2)
 Fabiano Caruana (ITA) 58% 59% 68%
 Hikaru Nakamura (USA) 39% 40% 49%
 Evgeny Tomashevsky (RUS) 2% 17% 42%
 Alexander Grischuk (RUS) 40% 41% 12%
 Boris Gelfand (ISR) 6% 6% 8%
 Sergey Karjakin (RUS) 5% 5% 7%
 Dmitry Jakovenko (RUS) 1% 1% 5%
 Anish Giri (NED) 14% 17% 5%
 Baadur Jobava (GEO) 0% 0% 1%
 Shakhriyar Mamedyarov (AZE) 6% 3% 1%
 Maxime Vachier-Lagrave (FRA) 15% 6% 1%
 Peter Svidler (RUS) 5% 2% 0%
 Teimour Radjabov (AZE) 0% 0% 0%
 Leinier Dominguez (CUB) 0% 0% 0%
 Dmitry Andreikin (RUS) 10% 3% 0%
 Rustam Kasimdzhanov (UZB) 0% 0% 0%

There is another, somewhat more subtle, ramification of Grischuk’s fall in the projected standings. It has become slightly less likely that the cutoff score needed to qualify for the Candidates Tournament will be extremely high. At the first rest day, when Grischuk (and his gaudy rating of 2810 at the time) was just one point off the lead, and still in legitimate contention, our model saw it as far more likely that he might post huge scores in both of the final two events, driving up the standards of qualification. Now of course Tomashevsky is still in a position to do just that, but with his lower rating he is projected as much less likely to follow up a great Tbilisi result with an equally great Khanty-Mansiysk result. Therefore, our projected cutoff has dropped 10 points. Our model now has the median points required to qualify for the Candidates as just 317, and now sees a (very remote) chance of someone qualifying with as little as 242 points, lower than our previously reported minimum. Of course there is still an extreme range of possible cutoffs, and noone should feel secure with a final score of, say, 320. In some of our simulations it still takes 392 points just to achieve second place! Here is a frequency graph of all the possible qualifying scores:

TbilisiRestTwo

One final consideration that we mentioned in our last post is the rating mark of 2800. Both Grischuk and Giri have fallen below it in the current live ratings, but they still have three rounds to rebound. Both are now underdogs to get their end-of-tournament rating (presumed to become official on the next rating list) back above the 2800 line, but neither is completely eliminated. Giri would need to score 2.5/3 in the final rounds, with the black pieces in two of those three games, and our model predicts him to do just that 14% of the time. Grischuk also needs to score 2.5/3, but has the benefit of two games with white, and so has a slightly better chance at 21%. Still, it now looks likely that the official March rating list will have only two 2800+ players on it – despite there having been five at the same time rated over 2800 in the live ratings earlier this month.

All told, the results over rounds five through eight have removed much of the drama from Tbilisi. Tomashevsky is now an overwhelming favorite to win the event, and has turned himself into a legitimate contender for one of the eventual Candidates Tournament spots. Of course he still has to navigate the last three rounds: he has roughly a 90% chance of at least sharing first place, but 10% is still 10%, and he has a job to do to close out the win. The other most tangible question is whether Grischuk can bounce back, manage at least a plus score in the last two rounds, move up the standings a bit, and enter Khanty-Mansiysk as a contender. We have about 20 hours until round 9 begins. In the meantime, hopefully this update gives you something to chew on during this rest day!

Advertisements

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 )

Google+ photo

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

Connecting to %s