| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 626. C K Pedersen vs I Efimov |
| ½-½ | 20 | 2009 | European Club Cup | B56 Sicilian |
| 627. L Pasko vs I Efimov |
| ½-½ | 65 | 2009 | European Club Cup | A54 Old Indian, Ukrainian Variation, 4.Nf3 |
| 628. I Efimov vs S J Barrett |
| 1-0 | 29 | 2009 | European Club Cup | B40 Sicilian |
| 629. C Cobb vs I Efimov |
| 1-0 | 48 | 2009 | European Club Cup | A13 English |
| 630. I Efimov vs R Buss |
| ½-½ | 25 | 2009 | European Club Cup | B53 Sicilian |
| 631. McShane vs I Efimov |
 | 0-1 | 40 | 2009 | European Team Championship | B20 Sicilian |
| 632. I Efimov vs I Miladinovic |
| 0-1 | 44 | 2009 | European Team Championship | A26 English |
| 633. V Georgiev vs I Efimov |
| ½-½ | 20 | 2009 | European Team Championship | D45 Queen's Gambit Declined Semi-Slav |
| 634. I Efimov vs J V Gunnarsson |
| ½-½ | 24 | 2009 | European Team Championship | A04 Reti Opening |
| 635. F Berend vs I Efimov |
| ½-½ | 68 | 2009 | European Team Championship | B43 Sicilian, Kan, 5.Nc3 |
| 636. I Efimov vs G Morrison |
| 1-0 | 18 | 2009 | European Team Championship | A15 English |
| 637. Nyback vs I Efimov |
| 1-0 | 40 | 2009 | European Team Championship | A40 Queen's Pawn Game |
| 638. I Efimov vs D Saiboulatov |
| 1-0 | 42 | 2009 | European Team Championship | C17 French, Winawer, Advance |
| 639. B Esen vs I Efimov |
| ½-½ | 36 | 2009 | European Team Championship | A55 Old Indian, Main line |
| 640. I Efimov vs M Godena |
| ½-½ | 16 | 2010 | 42nd Italian Team Championship | D25 Queen's Gambit Accepted |
| 641. I Efimov vs M Godena |
| ½-½ | 16 | 2010 | 42nd TCh-ITA Masters | D25 Queen's Gambit Accepted |
| 642. F Bentivegna vs I Efimov |
| ½-½ | 14 | 2010 | 42nd Italian Team Championship | C15 French, Winawer |
| 643. I Efimov vs D Rombaldoni |
| ½-½ | 10 | 2010 | 42nd Italian Team Championship | B14 Caro-Kann, Panov-Botvinnik Attack |
| 644. C Garcia Palermo vs I Efimov |
| 1-0 | 52 | 2010 | 42nd Italian Team Championship | A48 King's Indian |
| 645. I Efimov vs R Mantovani |
| ½-½ | 9 | 2010 | 42nd Italian Team Championship | D00 Queen's Pawn Game |
| 646. I Efimov vs D Collutiis |
| ½-½ | 5 | 2010 | 42nd Italian Team Championship | C49 Four Knights |
| 647. I Efimov vs G Grigore |
| ½-½ | 15 | 2010 | Open | A07 King's Indian Attack |
| 648. M Cebalo vs I Efimov |
| 1-0 | 36 | 2010 | Open | E24 Nimzo-Indian, Samisch |
| 649. W Elliott vs I Efimov |
| 0-1 | 53 | 2010 | Khanty-Mansiysk Olympiad | B42 Sicilian, Kan |
| 650. I Efimov vs A Kamara |
| 1-0 | 31 | 2010 | Khanty-Mansiysk Olympiad | D11 Queen's Gambit Declined Slav |
Kibitzing
