Postma, Jan
Current rating: 1657
Record: 34-26-1
| Grand Prix Brussels 2020 (pioneer) | starting rating: 1622 | |||
| round | table | opponent (rating) | result | Δrating |
| 1pioneer | 257 | Distefano, Giordano (1405) | Won 2-1 | +141636 |
| 2pioneer | 396 | Bris, Paul (1551) | Lost 0-2 | -201616 |
| 3pioneer | 654 | Roeterink, Arno (1502) | Won 2-1 | +161632 |
| 4pioneer | 351 | Amann, Aymeric (1610) | Won 2-0 | +181650 |
| 5pioneer | 171 | Boussaud, Eliott (1946) | Won 2-1 | +231673 |
| 6pioneer | 194 | Rinnen, Davide (1771) | Lost 1-2 | -161657 |
| 7pioneer | 202 | Lubbering, Dominik (1535) | Won 2-1 | +161673 |
| 8pioneer | 241 | Rouar, Julien (1823) | Lost 0-2 | -161657 |
| top | average opponent: 1643record: 5-3 | new rating: 1657 | ||
| Grand Prix Utrecht 2019 (ELD limited) | starting rating: 1599 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 547 | Muller, Moritz (1351) | Won 2-0 | +141613 |
| 2sealed | 341 | Schoots, Isha (1631) | Won 2-1 | +181631 |
| 3sealed | 12 | Warembourg, Romain (1350) | Lost 1-2 | -231608 |
| 4sealed | 450 | Gabriel, Aron (1541) | Won 2-1 | +171625 |
| 5sealed | 169 | Zarges, Felix (1698) | Won 2-0 | +191644 |
| 6sealed | 65 | Degrave, Clement (1531) | Won 2-1 | +161660 |
| 7sealed | 66 | England, Marc (1569) | Lost 1-2 | -191641 |
| 8sealed | 109 | Wright, Joe [ENG] (1598) | Lost 1-2 | -191622 |
| top | average opponent: 1533record: 5-3 | new rating: 1622 | ||
| Grand Prix Strasbourg 2019 (RNA limited) | starting rating: 1559 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 92 | Dushinin, Evgenii (1595) | Lost 0-2 | -171542 |
| 2sealed | 420 | Laghi, Riccardo (1482) | Won 2-1 | +171559 |
| 3sealed | 648 | Reibel, Alexis (1500) | Won 2-1 | +171576 |
| 4sealed | 241 | Thiele, Fabian (1712) | Lost 1-2 | -161560 |
| 5sealed | 485 | Bonaventure, Jean-Baptiste (1452) | Won 2-1 | +161576 |
| 6sealed | 404 | Faessler, Tim (1646) | Won 2-1 | +201596 |
| 7sealed | 218 | Verbiest, Bart (1649) | Won 2-1 | +191615 |
| 8sealed | 96 | Boelens, Jasper (1769) | Lost 0-2 | -161599 |
| top | average opponent: 1601record: 5-3 | new rating: 1599 | ||
| Grand Prix Utrecht 2017 (AER standard) | starting rating: 1579 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 217 | Hill, Steven (1410) | Won 2-0 | +151594 |
| 2standard | 227 | Smaranda, Adrian (1563) | Lost 0-2 | -181576 |
| 3standard | 425 | Costa, Tiago (1487) | Won 2-1 | +161592 |
| 4standard | 398 | Berger, Maximilien (1660) | Won 2-1 | +191611 |
| 5standard | 138 | Amendola, Michele (1798) | Lost 0-2 | -141597 |
| 6standard | 232 | Zivec, Josef (1536) | Lost 0-2 | -191578 |
| 7standard | 351 | Guan, Thomas Zhennan (1563) | Lost 0-2 | -191559 |
| top | average opponent: 1574record: 3-4 | new rating: 1559 | ||
| Grand Prix Utrecht 2015 (MM2 limited) | starting rating: 1602 | |||
| round | table | opponent (rating) | result | Δrating |
| 2sealed | 2045 | Fradl, Bernhard (1428) | Won 2-0 | +141616 |
| 3sealed | 2112 | Baglin, Arnaud (1854) | Lost 0-2 | -131603 |
| 4sealed | 2185 | Loffeld, Rik (1519) | Won 2-1 | +161619 |
| 5sealed | 2106 | de Gooijer, Dennis (1490) | Lost 0-2 | -201599 |
| 6sealed | 2159 | Jastrzebowski, Pawel (1520) | Lost 1-2 | -201579 |
| top | average opponent: 1562record: 2-3 | new rating: 1579 | ||
| Grand Prix Strasbourg 2014 (KTK limited) | starting rating: 1489 | |||
| round | table | opponent (rating) | result | Δrating |
| 2sealed | 153 | Schrijvers, Hans (1528) | Draw 1-1 | +11490 |
| 3sealed | 223 | Bertrand, Matthieu (1615) | Won 2-1 | +201510 |
| 4sealed | 108 | Kaufmann, Michael (1568) | Lost 0-2 | -171493 |
| 5sealed | 218 | Marinkovic, Goran (1488) | Won 2-0 | +181511 |
| 6sealed | 132 | Weber, Johannes (1536) | Won 2-0 | +191530 |
| 7sealed | 269 | Cuffini, Reynald (1572) | Won 2-1 | +181548 |
| 8sealed | 56 | Rolle, Christian (1458) | Won 2-1 | +171565 |
| 9sealed | 25 | Vanderhallen, Nicolas (1778) | Won 2-0 | +221587 |
| 10draft | 13 | Laguerre, Mathieu (1752) | Won 2-0 | +211608 |
| 11draft | 78 | Dahlke, Philipp (1687) | Lost 0-2 | -171591 |
| 12draft | 52 | Borek, Ales (1741) | Lost 0-2 | -151576 |
| 13draft | 101 | Marinari, Manuel (1748) | Lost 0-2 | -151561 |
| 14draft | 53 | van den Wouwer, Chris (1742) | Won 2-0 | +211582 |
| 15draft | 66 | Lihoreau, Ibai (1666) | Won 2-0 | +201602 |
| top | average opponent: 1634record: 9-4-1 | new rating: 1602 | ||
| Grand Prix Utrecht 2014 (M15 standard) | starting rating: 1463 | |||
| round | table | opponent (rating) | result | Δrating |
| 3standard | 96 | Simon, Laurent (1500) | Won 2-0 | +191482 |
| 4standard | 99 | Pieterse, Axel (1555) | Lost 0-2 | -171465 |
| 5standard | 115 | van der Meer, Thijs (1538) | Won 2-1 | +191484 |
| 6standard | 151 | Penman, Douglas (1513) | Won 2-0 | +191503 |
| 7standard | 72 | Berger, Maximilien (1592) | Lost 1-2 | -171486 |
| 8standard | 149 | Mills, James R (1545) | Lost 1-2 | -171469 |
| 9standard | 242 | Re, Manfredi (1568) | Won 2-1 | +201489 |
| top | average opponent: 1544record: 4-3 | new rating: 1489 | ||
| Grand Prix Vienna 2013 (THS standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 94 | Konrath, Gerald (1510) | Lost 0-2 | -181482 |
| 2standard | 419 | Groth, Johannes (1407) | Won 1-0 | +171499 |
| 3standard | 477 | Berka, Ivo (1502) | Lost 0-2 | -181481 |
| 4standard | 569 | Holzerbauer, Martin (1482) | Lost 0-2 | -181463 |
| top | average opponent: 1475record: 1-3 | new rating: 1463 | ||