1. Karjakin played some of the best defensive chess ever, finding resources where there appeared to be none.
2. Carlsen had become a bit lazy, relying too much on his stamina advantage to beat opponents (yes I do understand that is an odd notion of lazy!). Yet he had no real stamina advantage over Karjakin, who is of the same age and came to the match in very good physical shape. So Carlsen simply could not grind him down, and it took Carlsen the entire match to realize that.
3. Karjakin made very few attempts to achieve demonstrable, sharp advantages. That limited his total number of victories to one.
4. In the rapid tie-breaker — four consecutive games in the final day — Carlsen couldn’t try to win on stamina and simply showed he was the better player across many dimensions of the game. Karjakin posed him no problems at all in these contests.
5. Karjakin played as Carlsen’s equal for the twelve regular time control games. Yet I don’t think he will be back as a challenger. His style is too “drab” (Kasparov’s description) to get through all of the risk-rewarding tournaments to reach the final championship match again.
6. Perhaps rapid chess is the future of chess as a spectator sport. Four games in a row, each twenty-five minutes per player, plus increments. It was thrilling, and I watched on the train.
7. Putin finally lost one this year, let’s hope this reverses the trend.