Apropos Grischuk’s clock management, I always remember this post from Feb-18-2010, at page 13 of the thread for Topalov vs Grischuk, 2010:

<Eyal: Anand on Grischuk:

Is there anyone who *wouldn't* have wanted to see how the Ivanchuk/Grischuk would have turned out, had it been played to conclusion?

Yes.

"Great" meaning "in the league of Kasparov and Fischer"? This is worth taking into account:

http://en.chessbase.com/home/TabId/...

After 13 h3 Black's worst placed piece is his QB. This suggests that the move 13...Bd7 is to be considerd first. Then ...Rac8 may follow, supporting the move ...Nc4.

15 Qf3 attacks indirectly the f7 pawn and so pins the bishop on f6 after 15...Nxb2 16 Nb4 followed by Nd5. An alternative to 15...Be6 is 15...Ne5 followed by ...Bd7

19...Bxb3 devalues the knight because it cannot now go to c4. Instead of this, 19..Rac8 develops the rook.

21...a6 costs a tempo for development. Instead of this 21...Rfd8 supports the advance ...d5. It is time for Black to think about how to put his pawns to work.

I am a bloody patzer and amateur, but I even I know that - in case my opponent is very good in blitz - I have to avoid own time trouble or in a common time trouble that I have less time than he.

Invanchuk had roughly 20 minutes time plus on move 17 - 21, for his move 22 (22...Rac8) he consumed all his time plus. And there was no deeper reason to use so much time for this move. No direct threat, no really complicated position. Nothing special here. A simple development move. 22...Rac8, to be seen in a second, even for me. Ivanchuk lost the game exactly at this point.

More recent findings suggest that the picture isn't quite as bleak as you paint it. Neurons do disappear, but re-routing of signals occurs that compensates for this in varying degrees, while the broken synapses are replaced by new ones.

Also, how this process plays out is highly variable, with both genetic and behavioral factors in play. It is known, for example, that the brain acts almost like a muscle in the sense of "use it or lose it": The more one activates the connections, the more new ones will be forged.

In particular, learning new activities and skills, playing games that use one's mental faculties, solving logic (or chess!) puzzles, and learning or merely speaking languages (this is most notoriously true of Chinese, which because of its intonations uses both brain hemispheres), as well as the simple act of maintaining regular and active social communications, have all proved beneficial in retaining or sometimes even improving cognitive abilities well into old age.