Kossman, Matthew
Current rating: 1515
Record: 15-14
| Grand Prix Las Vegas 2018 (limited) (DOM limited) | starting rating: 1516 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 345 | Cohoon, Bob (1443) | Lost 0-2 | -201496 |
| 2sealed | 651 | Rosales, David (1596) | Lost 0-2 | -161480 |
| 3sealed | 833 | Wredberg, Gregory (1461) | Won 2-1 | +181498 |
| 4sealed | 663 | Adame, Gilbert (1486) | Won 2-0 | +181516 |
| 5sealed | 445 | McMullan, Kegan (1489) | Won 2-1 | +171533 |
| 6sealed | 285 | Ramos-Hlavaty, Jose (1517) | Lost 0-2 | -181515 |
| top | average opponent: 1499record: 3-3 | new rating: 1515 | ||
| Grand Prix Las Vegas 2017 (limited) (AKH limited) | starting rating: 1521 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 185 | Tran, Andrew (1568) | Lost 1-2 | -171504 |
| 2sealed | 626 | Banek, Gregory (1357) | Won 2-0 | +151519 |
| 3sealed | 673 | Sianez, Angel (1466) | Won 2-1 | +171536 |
| 4sealed | 457 | Beckfield, John (1505) | Won 2-0 | +181554 |
| 5sealed | 191 | Lehnert, Heiko (1482) | Lost 1-2 | -191535 |
| 6sealed | 528 | Wang, Robert (1486) | Won 2-1 | +171552 |
| 7sealed | 347 | Goetz, Adam (1556) | Lost 1-2 | -181534 |
| 8sealed | 501 | Moses, Trevor (1531) | Lost 0-2 | -181516 |
| top | average opponent: 1494record: 4-4 | new rating: 1516 | ||
| Grand Prix San Jose 2017 (AER limited) | starting rating: 1535 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 561 | Wright, William (1519) | Won 2-1 | +181553 |
| 2sealed | 263 | Nguyen, James (1732) | Lost 0-2 | -151538 |
| 3sealed | 425 | Kaiser, Ursa (1499) | Won 2-0 | +171555 |
| 4sealed | 467 | Mathews, Elias (1520) | Lost 0-2 | -181537 |
| 5sealed | 553 | Bonnema, Joshua (1464) | Lost 1-2 | -191518 |
| 6sealed | 629 | Li, Chen (1574) | Won 2-1 | +191537 |
| 7sealed | 434 | Lombardi, Anthony (1686) | Lost 0-2 | -161521 |
| top | average opponent: 1571record: 3-4 | new rating: 1521 | ||
| Grand Prix San Francisco 2007 (Time Spiral block) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1block | 21 | Custer, James (1491) | Won 2-0 | +181518 |
| 2block | 32 | Lewis, Jeremy (1536) | Won 2-0 | +181536 |
| 3block | 52 | Phung, Michael (1537) | Lost 0-2 | -181518 |
| 4block | 95 | Fuentes, Jeremy (1573) | Won 2-0 | +191537 |
| 5block | 83 | Richter, Donald (1472) | Lost 1-2 | -191518 |
| 6block | 111 | Duffey, Michael (1508) | Won 2-0 | +181536 |
| 7block | 111 | Sidher, Vikas (1519) | Won 2-0 | +171553 |
| 8block | 66 | Reiser, Adam (1541) | Lost 1-2 | -181535 |
| top | average opponent: 1522record: 5-3 | new rating: 1535 | ||