Berlin Candidates - Tiebreaks

In the previous post, Two Championship Qualifying Events, I gave the standings with two rounds to go in the 2018 Berlin Candidates Tournament. Everyone knew that a complicated tiebreak scenario was looming, but it was still too early to calculate the permutations.

The tiebreak rules play an important role in a Candidates tournament even when they are not invoked at the end of the event. Five years ago, after the London Candidates - Tiebreaks (April 2013), I wrote,

The 2013 London Candidates Tournament was a good show from start to end. The last three of the 14 rounds featured a neck-and-neck race between ex-World Champion Kramnik and GM Carlsen. [...] Carlsen's 13th round win gave him more than equality -- it also gave him the tiebreak advantage in case of an equal score after the last round.

Both players lost in the last round and Carlsen went on to challenge World Champion Anand and gain the title. Two years ago, in Moscow Candidates - Third Week (March 2016), I noted,

Going into the last round, the tiebreak situation was complicated. The two players leading the pack, Karjakin and Caruana, were due to play each other, so a win for either would be sufficient to win the event. In case of a draw, Karjakin would win on tiebreak if Anand, the third placed player, also drew. If Anand won, thereby achieving the same score as the other two, Caruana would win on tiebreak.

Karjakin beat Caruana and earned the right to challenge Carlsen. In the 2018 Berlin event, the standings before the last round, along with the pairings, are shown in the following chart taken from Chess24.com.

The players with a chance of winning the tournament (plus their scores going into the last round) are:-

8.0 Caruana
7.5 Mamedyarov, Karjakin
7.0 Ding Liren

It's still not easy to calculate each player's chances to win. I listed the tiebreak criteria in the '2013 London Candidates' post and they haven't changed since. For an overview of the possibilities today, see this article from yesterday: Candidates tiebreak scenarios (chessbase.com). Even for Chessbase, I'm not certain the situation is completely clear. The URL for the article says, 'Candidates Tiebreak Favours Mamedyarov', but the article starts, 'Advantage Caruana'. I tried to work out the odds for myself, but it requires manipulating a three-dimensional array, and I gave up.

In another post for today, one top player/organizer pleaded, Can We Please Fix the Tiebreak Situation at the Candidates? (gregshahade.wordpress.com):-

The only reasonable way to break a tie in an event of this magnitude is to play a tiebreak match for it. I could easily end the blog here, and the majority of the chess playing community would agree with me. However it’s not quite as simple as it seems.

Indeed, it's not so simple. Remember World Championship Fizzle (November 2016), when World Champion Carlsen effectively refused to engage in any combat during the last game of a title match and to take his chances in the tiebreak games? The whole chess world groaned, but Carlsen's strategy was straightforward. While his opponent, GM Karjakin, was preparing his opening for the last round game, Carlsen was preparing his openings for the tiebreak. The strategy worked brilliantly and Carlsen retained his title. Back to IM Greg Shahade's post, he continued,

What does it mean that there is no tiebreak after tomorrow’s games? It means that these are going to be the most intense classical chess games that you’ve ever seen.

I'm watching the games as I write this, and 'intense' is the right word. The tiebreak rules are working better here than they did for that 2016 Carlsen - Karjakin title match. IM Shahade goes on to suggest that, to maintain the tension into the last round,

The tiebreak should take place before the first round!

I'm on record favoring that scenario before a match, but I'm not sure how well it works before a tournament. Whatever the case, the situation two hours into the last round of the 2018 Candidates is no clearer than it was when the round started. Whether the tiebreak rules are finally invoked or not, they played a role and Carlsen's challenger will be known in the next few hours.