Koster, Olaf
Current rating: 1639
Record: 26-20-2 (GP) / 9-7 (professional)
| Grand Prix Brussels 2010 (WWK standard) | starting rating: 1646 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 795 | Jacobs, Maarten (1542) | Won 2-1 | +161662 |
| 2standard | 682 | Plummer, Richard (1487) | Lost 0-2 | -211641 |
| 3standard | 758 | Sorknaes, Johan (1500) | Won 2-0 | +161657 |
| 4standard | 783 | Ritzka, Simon (1660) | Lost 1-2 | -181639 |
| top | average opponent: 1547record: 2-2 | new rating: 1639 | ||
| Grand Prix Rotterdam 2009 (CON limited) | starting rating: 1672 | |||
| round | table | opponent (rating) | result | Δrating |
| 2sealed | 426 | Argel, Thomas (1514) | Won 2-1 | +151687 |
| 3sealed | 466 | Schulmerich, Felix (1609) | Lost 0-2 | -201667 |
| 4sealed | 509 | Wijsman, Gerwin (1503) | Lost 1-2 | -211646 |
| top | average opponent: 1542record: 1-2 | new rating: 1646 | ||
| Grand Prix Paris 2008 (ALA limited) | starting rating: 1662 | |||
| round | table | opponent (rating) | result | Δrating |
| 3sealed | 551 | Feenstra, Rens (1495) | Won 2-1 | +151677 |
| 4sealed | 550 | Chudoba, Martin (1705) | Lost 1-2 | -181659 |
| 5sealed | 606 | Becerril Alarcon, Antonio (1573) | Won 2-0 | +171676 |
| 6sealed | 571 | Leal, Daniel (1469) | Won 2-0 | +141690 |
| 7sealed | 519 | Fernandez, Alain (1563) | Won 2-1 | +161706 |
| 8sealed | 519 | Fischer, Jerome (1536) | Lost 1-2 | -211685 |
| 9sealed | 532 | Lybaert, Marijn (1970) | Lost 1-2 | -131672 |
| top | average opponent: 1616record: 4-3 | new rating: 1672 | ||
| Grand Prix Brussels 2008 (SHM limited) | starting rating: 1658 | |||
| round | table | opponent (rating) | result | Δrating |
| 4sealed | 4 | Tachau, Florian (1641) | Won 2-1 | +181676 |
| 5sealed | 32 | Schellens, Sam (1570) | Won 2-0 | +161692 |
| 6sealed | 12 | Wafo-Tapa, Guillaume (2217) | Lost 1-2 | -91683 |
| 7sealed | 29 | Pedrakowski, Pawel (1522) | Lost 0-2 | -211662 |
| top | average opponent: 1737record: 2-2 | new rating: 1662 | ||
| Grand Prix Vienna 2008 (extended) | starting rating: 1672 | |||
| round | table | opponent (rating) | result | Δrating |
| 3extended | 5 | De Bosscher, Cedric (1443) | Lost 1-2 | -231649 |
| 4extended | 133 | Dolenc, Andrej (1502) | Won 2-1 | +161665 |
| 5extended | 45 | Rodrigues, Fabio (1470) | Won 2-0 | +141679 |
| 6extended | 50 | Tollmann, Marcel (1501) | Lost 1-2 | -211658 |
| top | average opponent: 1479record: 2-2 | new rating: 1658 | ||
| 2007 World Championship (mixed) | starting rating: 1617 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 19 | Yu, Pi Hsiang (1528) | Lost 1-2 | -201597 |
| 2standard | 123 | Suarez, Felipe (1617) | Won 2-0 | +191616 |
| 3standard | 81 | Loh, Ryan (1479) | Lost 1-2 | -211595 |
| 4standard | 163 | Camargo, Andres (1401) | Won 2-1 | +151610 |
| 5standard | 127 | Melovski, Dimche (1513) | Won 2-1 | +161626 |
| 6draft | 151 | Amir, Elisha (1626) | Won 2-0 | +181644 |
| 7draft | 152 | Redford, Michael D (1552) | Won 2-1 | +161660 |
| 8draft | 119 | De Rosa, Antonino (1890) | Won 2-1 | +221682 |
| 9draft | 138 | Hofmeyr, David (1520) | Lost 0-2 | -201662 |
| 10draft | 38 | Scheel, Brandon (1690) | Won 2-0 | +181680 |
| 11draft | 85 | Camangon, Gerald (1684) | Lost 1-2 | -181662 |
| 12legacy | 42 | Cheon, Paul (2090) | Won 2-0 | +251687 |
| 13legacy | 28 | Tenenbaum, Amiel (2022) | Won 2-1 | +241711 |
| 14legacy | 18 | Chambers, Adam (1992) | Lost 1-2 | -131698 |
| 15legacy | 33 | Lybaert, Marijn (2028) | Lost 0-2 | -121686 |
| 16legacy | 39 | Hirosawa, Yuuta (1877) | Lost 0-2 | -141672 |
| top | average opponent: 1719record: 9-7 | new rating: 1672 | ||
| Grand Prix Krakow 2007 (LRW standard) | starting rating: 1627 | |||
| round | table | opponent (rating) | result | Δrating |
| 2standard | 563 | Ginter, Krzysztof (1500) | Won 2-0 | +161643 |
| 3standard | 539 | Jampula, Maciej (1467) | Won 2-0 | +151658 |
| 4standard | 506 | Nouzovsky, Zdenko (1446) | Lost 1-2 | -221636 |
| 5standard | 591 | Gargulak, Daniel (1536) | Lost 0-2 | -201616 |
| 6standard | 573 | Pasi, Maria Cristina (1489) | Won 2-0 | +161632 |
| 7standard | 576 | Maaten, Rogier (1811) | Lost 1-2 | -151617 |
| top | average opponent: 1542record: 3-3 | new rating: 1617 | ||
| Grand Prix Stockholm 2007 (FUT limited) | starting rating: 1601 | |||
| round | table | opponent (rating) | result | Δrating |
| 3sealed | 1 | Vallivaara, Visa (1562) | Won 2-1 | +171618 |
| 4sealed | 43 | Brucker, David (2069) | Draw 1-1 | +81626 |
| 5sealed | 54 | Thalling, Troels (1540) | Won 2-0 | +161642 |
| 6sealed | 26 | Grondahl, Erik (1701) | Won 2-1 | +191661 |
| 7sealed | 16 | Joens, Klaus (1827) | Lost 0-0 | -151646 |
| 8sealed | 39 | Nommensen, Knud (1587) | Lost 0-2 | -191627 |
| top | average opponent: 1714record: 3-2-1 | new rating: 1627 | ||
| Grand Prix Malmo 2006 (CSP limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 134 | Darnhofer, Robert (1494) | Won 2-0 | +181518 |
| 2sealed | 83 | Rosholm, Thomas (1740) | Draw 1-1 | +41522 |
| 3sealed | 72 | Rossmann, Juris (1555) | Won 2-1 | +181540 |
| 4sealed | 77 | Zogots, Martins (1583) | Lost 0-2 | -171523 |
| 5sealed | 127 | Liljefeldt, Olle (1517) | Won 2-1 | +181541 |
| 6sealed | 80 | Ganz, Andreas (1517) | Won 2-1 | +181559 |
| 7sealed | 50 | Janse, Love (1508) | Won 2-0 | +171576 |
| 8sealed | 32 | van Zutphen, Ronald (1660) | Won 2-0 | +191595 |
| 9draft | 3 | Polasek, Filip (1719) | Won 2-0 | +211616 |
| 10draft | 19 | Ringstrom, Harald (1631) | Won 2-0 | +181634 |
| 11draft | 17 | Sommerseth Orud, Kim (1687) | Lost 0-2 | -171617 |
| 12draft | 12 | Zogots, Martins (1665) | Lost 0-2 | -171600 |
| 13draft | 30 | Christoffersen, Tom Fr (1549) | Lost 1-2 | -191581 |
| 14draft | 23 | Polasek, Filip (1692) | Won 2-0 | +201601 |
| top | average opponent: 1608record: 9-4-1 | new rating: 1601 | ||