Koshak, Jacob
Current rating: 1569
Record: 34-31-1
| Regional Championships Atlanta 2023 (pioneer) | starting rating: 1610 | |||
| round | table | opponent (rating) | result | Δrating |
| 1pioneer | 517 | Marrero, Jorel (1447) | Lost 1-2 | -211589 |
| 2pioneer | 400 | Henderson, Christopher (1565) | Lost 1-2 | -181571 |
| 3pioneer | 575 | Emery, Joshua (1375) | Won 2-1 | +141585 |
| 4pioneer | 500 | Barone, Chris (1673) | Won 2-1 | +201605 |
| 5pioneer | 287 | Dunn, Lucas (1639) | Lost 1-2 | -181587 |
| 6pioneer | 412 | Punzo, Canaan (1592) | Lost 0-2 | -181569 |
| top | average opponent: 1548record: 2-4 | new rating: 1569 | ||
| Grand Prix Las Vegas 2019 (modern) (modern) | starting rating: 1595 | |||
| round | table | opponent (rating) | result | Δrating |
| 2modern | 74 | Belmontez, Luis (1366) | Won 2-0 | +141609 |
| 3modern | 144 | Segal, Jacob (1542) | Lost 0-2 | -191590 |
| 4modern | 314 | Koski, Emma (1523) | Won 2-0 | +161606 |
| 5modern | 207 | Weiser, Daniel (1950) | Won 2-0 | +241630 |
| 6modern | 141 | Tanha, Tyler (1557) | Won 2-1 | +171647 |
| 7modern | 106 | Ahmed, Konan (1588) | Lost 1-2 | -191628 |
| 8modern | 164 | Garcia, Patrick (1632) | Lost 0-2 | -181610 |
| top | average opponent: 1594record: 4-3 | new rating: 1610 | ||
| Grand Prix Atlanta 2018 (modern) | starting rating: 1583 | |||
| round | table | opponent (rating) | result | Δrating |
| 2modern | 218 | Clark, James (1463) | Lost 1-2 | -201563 |
| 3modern | 587 | Hill, Leon (1485) | Won 2-0 | +161579 |
| 4modern | 343 | Geyer, Breton (1538) | Lost 0-2 | -191560 |
| 5modern | 499 | Schnider, Jakob (1641) | Lost 1-2 | -161544 |
| 6modern | 484 | Senig, Alex (1487) | Won 2-1 | +171561 |
| 7modern | 451 | Fleischman, Will (1633) | Won 2-0 | +191580 |
| 8modern | 292 | Bridgman, Slater (1394) | Won 2-0 | +151595 |
| top | average opponent: 1520record: 4-3 | new rating: 1595 | ||
| Grand Prix Las Vegas 2018 (modern) (modern) | starting rating: 1571 | |||
| round | table | opponent (rating) | result | Δrating |
| 2modern | 184 | Reilly, Beau (1517) | Lost 0-2 | -191552 |
| 3modern | 1389 | Huckstep, Daniel (1499) | Won 2-1 | +171569 |
| 4modern | 533 | Bolanos, Christopher (1501) | Lost 1-2 | -191550 |
| 5modern | 529 | Alexander, Adam (1583) | Lost 1-2 | -181532 |
| 6modern | 694 | Roush, Brett (1453) | Won 2-0 | +171549 |
| 7modern | 501 | White, Barry (1480) | Won 2-0 | +171566 |
| 8modern | 426 | Reitenour, Chris (1518) | Won 2-0 | +171583 |
| top | average opponent: 1508record: 4-3 | new rating: 1583 | ||
| Grand Prix Oklahoma City 2017 (modern) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 463 | Kerr, James (1512) | Won 2-0 | +181518 |
| 2modern | 172 | Herrera, Matthew (1540) | Won 2-1 | +181536 |
| 3modern | 231 | Nicholas, Gabriel (1607) | Lost 0-2 | -161520 |
| 4modern | 394 | Macaraeg, Tad (1783) | Lost 1-2 | -141506 |
| 5modern | 514 | Rosburg, Derrick (1498) | Won 2-1 | +181524 |
| 6modern | 209 | Kageler, Aydin (1577) | Draw 1-1 | +11525 |
| 7modern | 291 | Carson, Dawson (1646) | Won 2-1 | +201545 |
| 8modern | 202 | Kemper, Jayson (1496) | Won 2-1 | +171562 |
| 9modern | 136 | Branham, Benjamin (1486) | Won 2-0 | +171579 |
| 10modern | 86 | Spears, Nicholas (1604) | Won 2-1 | +191598 |
| 11modern | 53 | Mispagel, Joey (1722) | Won 2-1 | +201618 |
| 12modern | 33 | Baeckstrom, Andrew (1903) | Lost 0-2 | -131605 |
| 13modern | 66 | McCollough, Sean (1676) | Lost 0-2 | -171588 |
| 14modern | 95 | Gurrola, Elliott (1634) | Lost 0-2 | -171571 |
| top | average opponent: 1620record: 8-5-1 | new rating: 1571 | ||
| Grand Prix Atlanta 2017 (XLN standard) | starting rating: 1515 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 264 | Johnson, Tarique (1443) | Won 2-1 | +171532 |
| 2standard | 276 | Hasani, Farid (1500) | Lost 0-2 | -191513 |
| 3standard | 540 | Temenak, Robert (1594) | Lost 0-2 | -161497 |
| 4standard | 510 | Brown, Dennis (1482) | Lost 1-2 | -191478 |
| 5standard | 553 | Brown, Andrew F (1555) | Won 2-0 | +201498 |
| 6standard | 429 | Norman, Allen (1627) | Won 2-1 | +201518 |
| 7standard | 348 | Ervin, Christopher (1501) | Lost 1-2 | -181500 |
| top | average opponent: 1529record: 3-4 | new rating: 1500 | ||
| Grand Prix Dallas-Fort Worth 2016 (modern) | starting rating: 1460 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 654 | Ford, Kaden (1500) | Won 2-1 | +191479 |
| 2modern | 308 | DiChello, Michael (1520) | Won 2-1 | +191498 |
| 3modern | 20 | Turner, Scott (1455) | Won 2-1 | +171515 |
| 4modern | 42 | Diesel, John (1417) | Lost 0-2 | -201495 |
| 5modern | 377 | Peterson, Samuel (1542) | Won 2-1 | +191514 |
| 6modern | 183 | Austin, Bobby (1563) | Won 2-1 | +191533 |
| 7modern | 145 | Nicholas, Gabriel (1671) | Won 2-1 | +201553 |
| 8modern | 58 | Pardee, Samuel (2030) | Lost 0-2 | -91544 |
| 9modern | 62 | Doan, Tuan (1693) | Won 2-1 | +201564 |
| 10modern | 53 | Lamb, Dustin (1570) | Lost 0-2 | -181546 |
| 11modern | 135 | Bogner, Ryan (1840) | Lost 0-2 | -121534 |
| 12modern | 155 | Jorn, Christian (1503) | Lost 0-2 | -191515 |
| top | average opponent: 1609record: 7-5 | new rating: 1515 | ||
| Grand Prix Houston 2016 (OGW standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 166 | Kilburn, Brian (1363) | Won 1-0 | +161516 |
| 2standard | 139 | Robin, Alex (1469) | Lost 0-2 | -191497 |
| 3standard | 611 | Mendiola, Jeremiah (1500) | Lost 0-2 | -181479 |
| 4standard | 765 | Ham, Ethan (1484) | Won 2-0 | +181497 |
| 5standard | 424 | Summers, Gary (1503) | Lost 0-1 | -181479 |
| 6standard | 96 | Jones, Bryson (1442) | Lost 0-2 | -191460 |
| top | average opponent: 1460record: 2-4 | new rating: 1460 | ||