Masumoto, Ken
Current rating: 1619
Record: 38-35
| Regional Championships Dallas 2023 (pioneer) | starting rating: 1580 | |||
| round | table | opponent (rating) | result | Δrating |
| 1pioneer | 398 | Stenstrom, Grant (1449) | Won 2-1 | +151595 |
| 2pioneer | 231 | Angel, Ben (1513) | Won 2-0 | +171612 |
| 3pioneer | 133 | Islas, Leonard (1454) | Lost 0-2 | -211591 |
| 4pioneer | 216 | Aprim, Matthew (1373) | Won 2-1 | +141605 |
| 5pioneer | 78 | Johnson, DeShawn (1561) | Lost 0-2 | -191586 |
| 6pioneer | 129 | Metyko, Walker (1651) | Won 2-1 | +201606 |
| 7pioneer | 174 | Jarvis, Kasey (1709) | Won 2-1 | +191625 |
| 8pioneer | 125 | Cusick, Brian (1790) | Won 2-1 | +211646 |
| 9pioneer | 27 | Strong, Tom (1752) | Won 2-0 | +201666 |
| 10pioneer | 15 | Kessler, Tom (1899) | Lost 1-2 | -141652 |
| 11pioneer | 37 | Moughon, Evart (1823) | Lost 1-2 | -141638 |
| 12pioneer | 83 | Li, Michael (1593) | Lost 0-2 | -191619 |
| top | average opponent: 1630record: 7-5 | new rating: 1619 | ||
| Grand Prix Las Vegas 2019 (modern) (modern) | starting rating: 1476 | |||
| round | table | opponent (rating) | result | Δrating |
| 2modern | 5 | Zimmerman, Chris (1610) | Won 2-1 | +201496 |
| 3modern | 109 | Berni, Roberto (1551) | Won 2-1 | +191515 |
| 4modern | 192 | Rudiger, Alexander (1540) | Won 2-0 | +191534 |
| 5modern | 19 | Chavez, Anthony (1640) | Lost 1-2 | -161518 |
| 6modern | 194 | Boston, Steven (1676) | Won 2-0 | +211539 |
| 7modern | 122 | Zabawa, Steve (1587) | Won 2-0 | +191558 |
| 8modern | 43 | Wang, John (1607) | Lost 0-2 | -181540 |
| 9modern | 58 | Park, Coleman (1621) | Won 2-1 | +201560 |
| 10modern | 2040 | Corvese, Harry (1920) | Won 2-0 | +241584 |
| 11modern | 2050 | Knapp, Jace (1670) | Lost 0-2 | -161568 |
| 12modern | 2056 | Sullano, Andrew (1855) | Lost 1-2 | -131555 |
| 13modern | 2091 | Nettles, Logan (1895) | Lost 1-2 | -121543 |
| 14modern | 2107 | Tremblay, John (1570) | Won 2-0 | +181561 |
| 15modern | 2084 | Buddensiek, Peter (1591) | Won 2-1 | +191580 |
| top | average opponent: 1667record: 9-5 | new rating: 1580 | ||
| Grand Prix Seattle 2019 (MH1 limited) | starting rating: 1488 | |||
| round | table | opponent (rating) | result | Δrating |
| B2sealed | 330 | Cornejo, Christopher (1563) | Won 2-1 | +201508 |
| B3sealed | 201 | Miller, Drew (1548) | Lost 1-2 | -181490 |
| B4sealed | 161 | Holden, Kyle (1532) | Won 2-0 | +191509 |
| B5sealed | 73 | Lee, Joon Soo (1816) | Lost 0-2 | -121497 |
| B6sealed | 213 | Sendaydiego, Curt (1352) | Lost 1-2 | -211476 |
| top | average opponent: 1562record: 2-3 | new rating: 1476 | ||
| Grand Prix Portland 2018 (modern) | starting rating: 1470 | |||
| round | table | opponent (rating) | result | Δrating |
| 3modern | 11 | Brunson, Damyan (1666) | Lost 1-2 | -151455 |
| 4modern | 232 | Chin, Jim (1575) | Won 2-0 | +211476 |
| 5modern | 114 | Kauffman, Thomas (1575) | Won 2-1 | +191495 |
| 6modern | 178 | Zell, Susan (1480) | Won 2-0 | +181513 |
| 7modern | 59 | Yoo, Bradley (1788) | Lost 1-2 | -131500 |
| 8modern | 133 | Steier, Terry (1858) | Lost 0-2 | -121488 |
| top | average opponent: 1657record: 3-3 | new rating: 1488 | ||
| Grand Prix Seattle 2018 (standard) (RIX standard) | starting rating: 1499 | |||
| round | table | opponent (rating) | result | Δrating |
| 3standard | 230 | Cobb, Evan (1500) | Lost 0-2 | -181481 |
| 4standard | 367 | Brisson, Jason (1463) | Won 2-0 | +181499 |
| 5standard | 160 | Mihu, Jonathon (1585) | Lost 1-2 | -161483 |
| 6standard | 301 | Yee-Fong, Paul (1556) | Lost 0-2 | -171466 |
| 7standard | 368 | Campbell, Drake (1432) | Won 2-1 | +171483 |
| 8standard | 271 | Watanabe, Takanori (1743) | Lost 0-2 | -131470 |
| top | average opponent: 1547record: 2-4 | new rating: 1470 | ||
| Grand Prix Portland 2017 (XLN standard) | starting rating: 1521 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 51 | Gillespie, Chris (1500) | Lost 1-2 | -181503 |
| 2standard | 577 | Vasquez, Juan (1482) | Won 2-1 | +181521 |
| 3standard | 618 | Zelick, Aaron (1603) | Lost 1-2 | -171504 |
| 4standard | 581 | Kelley, Jonathan (1483) | Lost 0-2 | -181486 |
| 5standard | 623 | Van Orman, Pandora (1418) | Won 2-1 | +171503 |
| 6standard | 534 | Hayden, Josh (1484) | Lost 1-2 | -191484 |
| 7standard | 591 | Gray, Shane (1326) | Won 2-0 | +151499 |
| top | average opponent: 1471record: 3-4 | new rating: 1499 | ||
| Grand Prix Denver 2017 (HOU standard) | starting rating: 1504 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 337 | Coltran, Marty (1402) | Won 2-0 | +171521 |
| 2standard | 36 | Kopp, Jason (1517) | Won 2-0 | +171538 |
| 3standard | 52 | Mahaffey, Robert (1511) | Lost 1-2 | -181520 |
| 4standard | 184 | Ray, Adam (1567) | Lost 0-2 | -171503 |
| 5standard | 437 | Pham, Khoa (1542) | Won 2-0 | +191522 |
| 6standard | 225 | Stittsworth, Brian (1480) | Won 2-0 | +171539 |
| 7standard | 121 | Hibbard, Dalton (1594) | Lost 0-2 | -171522 |
| 8standard | 184 | Meis, Scott (1491) | Won 2-1 | +171539 |
| 9standard | 201 | Belfance, Christopher (1550) | Lost 1-2 | -181521 |
| top | average opponent: 1517record: 5-4 | new rating: 1521 | ||
| Grand Prix Vancouver 2017 (modern) | starting rating: 1480 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 2010 | Baker, Justin (1564) | Won 2-1 | +201500 |
| 2modern | 2053 | Patrick, Gary (1603) | Lost 0-2 | -161484 |
| 3modern | 2523 | Heldsinger, Christopher (1520) | Lost 1-2 | -181466 |
| 4modern | 2491 | Green, Jason (1484) | Lost 0-2 | -171449 |
| 5modern | 2638 | Munson, Stacy (1476) | Won 2-1 | +181467 |
| 6modern | 2591 | Castro, Angel (1532) | Won 2-0 | +191486 |
| 7modern | 2365 | Mata, Hunter (1495) | Won 2-0 | +181504 |
| 8modern | 2236 | Towle, Truman (1488) | Lost 1-2 | -181486 |
| 9modern | 2365 | Morse, Samuel (1502) | Won 2-0 | +181504 |
| top | average opponent: 1518record: 5-4 | new rating: 1504 | ||
| Grand Prix Seattle-Tacoma 2015 (legacy) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 206 | Dignam, Josh (1487) | Lost 0-2 | -181482 |
| 2legacy | 614 | Otteson, Ben (1430) | Won 2-0 | +171499 |
| 3legacy | 600 | Omori, Quinn (1499) | Lost 1-2 | -181481 |
| 4legacy | 777 | Goodsell, Matthew (1440) | Lost 1-2 | -191462 |
| 5legacy | 778 | Carr, Troy (1468) | Won 2-0 | +181480 |
| top | average opponent: 1465record: 2-3 | new rating: 1480 | ||