O'Brien, Sean
Current rating: 1515
Record: 34-35-4
Grand Prix Atlanta 2012Grand Prix Washington DC 2013Grand Prix New Jersey 2014Grand Prix Baltimore 2014Grand Prix Seattle-Tacoma 2015Grand Prix Oakland 2016Grand Prix Chiba 2016Grand Prix Las Vegas 2017 (legacy)Grand Prix Seattle 2018 (legacy)Grand Prix Shizuoka 2018 (legacy)Grand Prix Atlanta 2019Regional Championships Dallas 2023
| Regional Championships Dallas 2023 (pioneer) | starting rating: 1507 | |||
| round | table | opponent (rating) | result | Δrating |
| 1pioneer | 381 | Kinsey, David (1526) | Lost 1-2 | -181489 |
| 2pioneer | 495 | Moughon, Evart (1758) | Lost 1-2 | -131476 |
| 3pioneer | 532 | McCoy, Jeffrey (1593) | Lost 0-2 | -161460 |
| 4pioneer | 525 | Ruth, Eric (1446) | Won 2-1 | +181478 |
| 5pioneer | 508 | Wagner-Krankel, Robert (1541) | Won 2-0 | +191497 |
| 6pioneer | 306 | Bridges, Dylan (1495) | Won 2-0 | +181515 |
| 7pioneer | 334 | PenDragon, Jesse (1506) | Won 2-0 | +181533 |
| 8pioneer | 171 | Cushing, Mickey (1544) | Lost 1-2 | -181515 |
| 9pioneer | 220 | Fraley, Ben (1505) | Draw 0-0 | 01515 |
| top | average opponent: 1546record: 4-4-1 | new rating: 1515 | ||
| Grand Prix Atlanta 2019 (legacy) | starting rating: 1543 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 33 | Raczka, David (1468) | Won 2-0 | +171560 |
| 2legacy | 38 | Doller, Warren (1646) | Lost 0-2 | -171543 |
| 3legacy | 306 | Swanson, William (1500) | Lost 1-2 | -191524 |
| 4legacy | 436 | Kuryl-Champine, Brock (1548) | Lost 0-2 | -171507 |
| top | average opponent: 1540record: 1-3 | new rating: 1507 | ||
| Grand Prix Shizuoka 2018 (legacy) (legacy) | starting rating: 1569 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 41 | Nomura, Hiroshi (1521) | Lost 0-2 | -191550 |
| 2legacy | 508 | Takahashi, Toshiyuki (1361) | Won 2-1 | +151565 |
| 3legacy | 523 | Endoh, Hiroki (1551) | Lost 0-2 | -181547 |
| 4legacy | 497 | Ochi, Kensuke (1449) | Won 2-0 | +161563 |
| 5legacy | 326 | King, Graham (1451) | Lost 1-2 | -201543 |
| top | average opponent: 1467record: 2-3 | new rating: 1543 | ||
| Grand Prix Seattle 2018 (legacy) (legacy) | starting rating: 1512 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 166 | Trie, David (1586) | Draw 1-1 | +11513 |
| 2legacy | 392 | Faria, Joah (1464) | Won 2-0 | +171530 |
| 3legacy | 349 | Tse, Stephen (1543) | Won 2-1 | +191549 |
| 4legacy | 193 | Jerome, Alec (1633) | Lost 0-2 | -171532 |
| 5legacy | 356 | Eakins, Evan (1520) | Won 2-0 | +181550 |
| 6legacy | 229 | Davila, Gilbert (1685) | Won 2-1 | +201570 |
| 7legacy | 139 | Peterson, Kyle (1527) | Won 2-0 | +171587 |
| 8legacy | 84 | Thompson, Zach (1576) | Lost 1-2 | -181569 |
| top | average opponent: 1567record: 5-2-1 | new rating: 1569 | ||
| Grand Prix Las Vegas 2017 (legacy) (legacy) | starting rating: 1469 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 427 | Hidalgo, Joseph (1482) | Won 1-0 | +181487 |
| 2legacy | 257 | Niyazov, Igor (1571) | Lost 1-2 | -161471 |
| 3legacy | 830 | Mendez, James (1489) | Won 2-0 | +181489 |
| 4legacy | 490 | Slone, Ryan (1666) | Won 2-1 | +211510 |
| 5legacy | 437 | Jones, Brock (1573) | Won 2-0 | +191529 |
| 6legacy | 184 | Ogawa, Satoshi (1566) | Lost 1-2 | -171512 |
| top | average opponent: 1558record: 4-2 | new rating: 1512 | ||
| Grand Prix Chiba 2016 (legacy) | starting rating: 1487 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 696 | Nanamori, Kouhei (1629) | Won 2-1 | +211508 |
| 2legacy | 68 | Ohba, Hiroshi (1505) | Lost 1-2 | -181490 |
| 3legacy | 691 | Hiraoka, Shigenori (1495) | Won 2-1 | +181508 |
| 4legacy | 496 | Nakatani, Hiroki (1382) | Lost 1-2 | -211487 |
| 5legacy | 924 | Kawano, Hiroki (1449) | Lost 0-2 | -181469 |
| top | average opponent: 1492record: 2-3 | new rating: 1469 | ||
| Grand Prix Oakland 2016 (BFZ standard) | starting rating: 1455 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 107 | Quach, Joseph (1500) | Lost 0-2 | -171438 |
| 2standard | 586 | Heiser, Izzak (1482) | Won 2-0 | +181456 |
| 3standard | 592 | Brackeen, Kevin (1500) | Won 2-1 | +191475 |
| 4standard | 480 | Cremeans, Gregory (1531) | Won 2-1 | +191494 |
| 5standard | 128 | Chung, Brian (1629) | Won 2-0 | +211515 |
| 6standard | 71 | Guevarra, Nicolo (1832) | Lost 1-2 | -131502 |
| 7standard | 290 | Nguyen, Minh D (1616) | Lost 0-2 | -161486 |
| 8standard | 349 | Webster, Jon (1551) | Won 2-0 | +191505 |
| 9standard | 205 | Dorn, Victoria (1485) | Lost 0-2 | -181487 |
| top | average opponent: 1569record: 5-4 | new rating: 1487 | ||
| Grand Prix Seattle-Tacoma 2015 (legacy) | starting rating: 1469 | |||
| round | table | opponent (rating) | result | Δrating |
| 3legacy | 190 | Valencia, Omar (1446) | Lost 0-2 | -181451 |
| 4legacy | 344 | Singson, Jereme Ivin (1518) | Won 2-0 | +191470 |
| 5legacy | 391 | Hosejka, Vadim (1593) | Draw 1-1 | +21472 |
| 6legacy | 256 | Ahrens, Jonathan (1494) | Lost 0-2 | -171455 |
| top | average opponent: 1512record: 1-2-1 | new rating: 1455 | ||
| Grand Prix Baltimore 2014 (KTK limited) | starting rating: 1503 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 95 | Pastorinni, Luckas (1630) | Lost 1-2 | -151488 |
| 2sealed | 304 | Culver, Bryan (1437) | Lost 0-2 | -191469 |
| 3sealed | 579 | Horine, Keith (1465) | Won 2-0 | +181487 |
| 4sealed | 498 | Wanich, Mark (1529) | Lost 0-2 | -181469 |
| top | average opponent: 1515record: 1-3 | new rating: 1469 | ||
| Grand Prix New Jersey 2014 (legacy) | starting rating: 1561 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 240 | Chowdhry, Shawn (1500) | Lost 1-2 | -191542 |
| 2legacy | 405 | Havrilla, Matthew (1463) | Lost 1-2 | -201522 |
| 3legacy | 625 | McKeone, Keith (1464) | Lost 0-2 | -191503 |
| top | average opponent: 1476record: 0-3 | new rating: 1503 | ||
| Grand Prix Washington DC 2013 (legacy) | starting rating: 1539 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 343 | Shendock, Nicholaus (1500) | Won 2-0 | +171556 |
| 2legacy | 73 | McNamara, Brendan (1539) | Won 2-1 | +181574 |
| 3legacy | 605 | Dupal, Stephen (1544) | Won 2-0 | +171591 |
| 4legacy | 23 | Wiper, Charles (1684) | Won 2-0 | +201611 |
| 5legacy | 115 | Thompson, Kale (1614) | Lost 0-2 | -181593 |
| 6legacy | 191 | Van Fleet, Adam (1699) | Lost 0-2 | -161577 |
| 7legacy | 345 | Doolittle, Shelby (1681) | Lost 1-2 | -161561 |
| top | average opponent: 1609record: 4-3 | new rating: 1561 | ||
| Grand Prix Atlanta 2012 (legacy) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 61 | Vasquez, Jeremiah (1464) | Draw 1-1 | -11499 |
| 2legacy | 196 | Flagg, Matt A (1466) | Won 2-1 | +181517 |
| 3legacy | 157 | Orrison, Gerald (1501) | Lost 1-2 | -191498 |
| 4legacy | 328 | Waechter, Kurt (1430) | Won 2-0 | +171515 |
| 5legacy | 241 | Mendoza, Robert (1518) | Won 2-0 | +181533 |
| 6legacy | 167 | Guthrie, Kendal (1499) | Lost 0-2 | -181515 |
| 7legacy | 228 | Meier, Ryan (1460) | Won 2-1 | +171532 |
| 8legacy | 169 | DeGraff, Ian (1557) | Won 2-0 | +181550 |
| 9legacy | 122 | Duke, Reid (1945) | Lost 0-2 | -111539 |
| top | average opponent: 1538record: 5-3-1 | new rating: 1539 | ||