The Tal Memorial finishes tonight and it has revealed at least one thing to me. Previously I suggested that double round robins encouraged more conservative play than single round robins, in that players were happy to draw with Black and then fight against the same opponent with White (or course their opponent is probably using the same strategy).
However the gathering of 10 of the worlds top players has seen just as many draws, if not more. After 7 rounds there were 5 players tied for first on +1, and in round 8 only Aronian v Svidler was decisive. Of course most of the draws were still pretty hard fought (No draw offers before move 40 is a tournament condition), but lack of decisive games in the later half of the tournament indicates, well, something.
Probably the outstanding result in this regard is Viswanathan Anand's +0=9-0 result. The normal explanation is that he keeps his powder dry for upcoming World Championship matches, but I'm sure Tigran Petrosian is smiling somewhere in the afterlife!
Here is his final round game against his upcoming World Championship challenger Boris Gelfand.
Gelfand, Boris - Anand, Viswanathan
6th Tal Memorial Moscow RUS (9), 25.11.2011
1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 Be7 5. Bf4 O-O 6. a3 dxc4 7. e4 b5 8. Nxb5 Nxe4 9. Bxc4 Nd6 10. Bd3 Nxb5 11. Bxb5 Bb7 12. O-O Nd7 13. Rc1 Bd6 14. Bg3 Rb8 15. Ne5 Nxe5 16. dxe5 Be7 17. Qxd8 Bxd8 18. Bc4 Be7 19. Rfd1 Rfd8 20. Bf4 Rxd1+ 21. Rxd1 Bc6 22. Rd2 a5 23. Kf1 Kf8 24. Be3 Ke8 25. f4 a4 26. Ba7 Ra8 27. Be3 Rb8 28. Ba7 Ra8 29. Be3 1/2-1/2