Sierk, Kolja
Current rating: 1559
Record: 33-34-1
| Grand Prix Utrecht 2017 (AER standard) | starting rating: 1534 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 260 | Sellers, Dennis (1449) | Won 2-0 | +161550 |
| 2standard | 182 | Rosengren, Lars (1711) | Lost 0-2 | -151535 |
| 3standard | 363 | Klocker, Mario (1617) | Lost 0-2 | -161519 |
| 4standard | 555 | Chernykh, Vadim (1487) | Won 2-1 | +171536 |
| 5standard | 408 | Boucetta, Joackim (1703) | Lost 1-2 | -151521 |
| 6standard | 469 | Gerecke, Piet (1625) | Won 2-1 | +201541 |
| 7standard | 358 | Primot, Armel (1660) | Lost 0-2 | -161525 |
| 8standard | 393 | Collins, James (1457) | Won 2-0 | +171542 |
| 9standard | 354 | Galand, Nathan (1502) | Won 2-0 | +171559 |
| top | average opponent: 1579record: 5-4 | new rating: 1559 | ||
| Grand Prix Madrid 2016 (KLD standard) | starting rating: 1512 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 117 | Urena, Abraham (1698) | Won 2-1 | +221534 |
| 2standard | 206 | Orlandi, Yannick (1600) | Lost 1-2 | -171517 |
| 3standard | 603 | Costa, Tiago (1526) | Lost 0-2 | -181499 |
| 4standard | 666 | Zegarra, Renato (1389) | Won 2-0 | +161515 |
| 5standard | 528 | Caillaba, Germain (1685) | Lost 0-2 | -151500 |
| 6standard | 522 | Espinha, Andre (1419) | Won 2-1 | +171517 |
| 7standard | 385 | Bizet, Philippe (1486) | Won 2-0 | +171534 |
| 8standard | 276 | Velikov, Martin (1558) | Lost 1-2 | -171517 |
| 9standard | 396 | Pinero Orellana, Antonio (1485) | Won 2-1 | +171534 |
| top | average opponent: 1538record: 5-4 | new rating: 1534 | ||
| Grand Prix Warsaw 2016 (KLD standard) | starting rating: 1399 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 43 | Wrzosek, Jacek (1501) | Lost 1-2 | -161383 |
| 2standard | 321 | Rebizant, Artur (1482) | Won 2-1 | +201403 |
| 3standard | 376 | Fafalios, Pavlos (1596) | Won 2-0 | +211424 |
| 4standard | 223 | Mastrodomenico, Luigi (1554) | Won 2-1 | +211445 |
| 5standard | 91 | Gorokhovskyy, Kostyantyn (1458) | Won 2-1 | +181463 |
| 6standard | 153 | Ofmanski, Piotr (1547) | Won 2-0 | +191482 |
| 7standard | 31 | Wang, Haokang (1744) | Lost 1-2 | -131469 |
| 8standard | 108 | Maurice, Leo (1528) | Draw 1-1 | +11470 |
| 9standard | 130 | Schetka, Evgeny (1659) | Won 2-0 | +211491 |
| 10standard | 81 | Lewandowski, Bartlomiej (1823) | Lost 0-2 | -121479 |
| 11standard | 124 | Fedarovich, Dzmitry (1610) | Won 2-0 | +211500 |
| 12standard | 93 | Mosna, Karol (1591) | Lost 0-2 | -171483 |
| 13standard | 118 | Babbi, Aureliano (1551) | Won 2-0 | +201503 |
| 14standard | 89 | Worsnop, George (1636) | Won 2-0 | +201523 |
| 15standard | 69 | Plisov, Oleg (1950) | Lost 0-2 | -111512 |
| top | average opponent: 1615record: 9-5-1 | new rating: 1512 | ||
| Grand Prix Brussels 2015 (BFZ standard) | starting rating: 1446 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 298 | Koster, Jeroen (1446) | Won 0-0 | +181464 |
| 2standard | 300 | McLean, Daquan (1525) | Lost 0-0 | -171447 |
| 3standard | 652 | De Ligne, Marvic (1501) | Won 2-0 | +191466 |
| 4standard | 268 | Kobielski, Mateusz (1471) | Lost 1-2 | -181448 |
| 5standard | 535 | Berladyn, Vincent (1550) | Won 2-0 | +201468 |
| 6standard | 445 | Neville, Perry (1511) | Lost 1-2 | -171451 |
| 7standard | 452 | Denys, Adriaan (1504) | Lost 1-2 | -171434 |
| 8standard | 446 | Schmidt, Tim (1461) | Lost 0-2 | -181416 |
| 9standard | 422 | Pineiro, Andres (1471) | Lost 0-2 | -171399 |
| top | average opponent: 1493record: 3-6 | new rating: 1399 | ||
| Grand Prix Prague 2015 (ORI standard) | starting rating: 1415 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 15 | Graf, Martin (1500) | Won 2-0 | +191434 |
| 2standard | 292 | Vardzik, Marek (1595) | Won 2-1 | +211455 |
| 3standard | 308 | Vignudelli, Mattia (1599) | Lost 0-2 | -151440 |
| 4standard | 196 | Stefankova, Jaroslava (1426) | Lost 0-2 | -181422 |
| 5standard | 510 | Antal, Roland (1413) | Won 2-1 | +181440 |
| 6standard | 365 | Stepien, Szymon (1520) | Lost 0-2 | -171423 |
| 7standard | 359 | Dusek, Lukas (1611) | Won 2-0 | +211444 |
| 8standard | 269 | Holtz, Henning (1434) | Lost 0-2 | -181426 |
| 9standard | 296 | Lukes, Dan (1510) | Won 2-1 | +201446 |
| top | average opponent: 1512record: 5-4 | new rating: 1446 | ||
| Grand Prix Krakow 2015 (DTK standard) | starting rating: 1484 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 127 | Mauracher, Stephan (1562) | Lost 1-2 | -171467 |
| 2standard | 295 | Judzinski, Damian (1465) | Lost 0-2 | -181449 |
| 3standard | 503 | Doskocil, Filip (1466) | Won 2-1 | +191468 |
| 4standard | 462 | Feher, Attila (1529) | Lost 1-2 | -171451 |
| 5standard | 491 | Banasiak, Ewelina (1324) | Won 2-1 | +161467 |
| 6standard | 431 | Dziekan, Lukasz (1628) | Lost 0-2 | -161451 |
| 7standard | 375 | Bakalarz, Mikolaj (1464) | Lost 0-2 | -171434 |
| 8standard | 346 | Nadstawny, Rafal (1393) | Lost 0-2 | -191415 |
| top | average opponent: 1479record: 2-6 | new rating: 1415 | ||
| Grand Prix Bochum 2012 (RTR standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 618 | Krueler, Jens (1509) | Won 2-1 | +181518 |
| 2standard | 748 | Parfus, Leos (1443) | Won 2-1 | +171535 |
| 3standard | 719 | de Graat, Julien (1570) | Won 2-0 | +181553 |
| 4standard | 536 | Vornhusen, Gunnar (1417) | Lost 0-2 | -201533 |
| 5standard | 649 | Klocker, Elias (1858) | Lost 0-2 | -121521 |
| 6standard | 660 | Marx, Florian (1473) | Lost 0-2 | -191502 |
| 7standard | 698 | Roder, Hans-Martin (1551) | Lost 0-2 | -171485 |
| 8standard | 731 | Keppel, James (1481) | Won 2-0 | +181503 |
| 9standard | 684 | Tischer, Andreas (1469) | Lost 1-2 | -191484 |
| top | average opponent: 1530record: 4-5 | new rating: 1484 | ||