Underdown, Zachary
Current rating: 1498
Record: 11-13-1
| Grand Prix Portland 2018 (modern) | starting rating: 1437 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 7 | Tidd, Donald (1500) | Won 2-0 | +191456 |
| 2modern | 38 | Kyaw, Seaver (1521) | Won 2-0 | +191475 |
| 3modern | 125 | Buckman, Creyson (1577) | Won 2-0 | +201495 |
| 4modern | 161 | Martinez, Jonathan 7193 (1484) | Won 2-1 | +181513 |
| 5modern | 49 | Wijaya, Vidianto (2067) | Lost 1-2 | -91504 |
| 6modern | 99 | Kneale, Tyler (1551) | Won 2-0 | +191523 |
| 7modern | 114 | Caswell, Ben (1567) | Won 2-0 | +191542 |
| 8modern | 54 | Lossett, Joe (1932) | Lost 0-2 | -121530 |
| 9modern | 114 | Blue, Holly (1578) | Lost 0-2 | -171513 |
| 10modern | 114 | Jones, Anders (1681) | Lost 1-2 | -151498 |
| top | average opponent: 1646record: 6-4 | new rating: 1498 | ||
| Grand Prix Los Angeles 2018 (M19 standard) | starting rating: 1470 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 312 | Supernak, Stanley (1499) | Lost 0-2 | -181452 |
| 2standard | 375 | Freitas, Andrew (1517) | Won 2-0 | +201472 |
| 3standard | 363 | Franklin, Gabriel (1483) | Draw 1-1 | 01472 |
| 4standard | 351 | Simons, Michael (1502) | Lost 1-2 | -181454 |
| 5standard | 413 | Cavender, Mason (1483) | Lost 0-2 | -171437 |
| top | average opponent: 1497record: 1-3-1 | new rating: 1437 | ||
| Grand Prix Las Vegas 2018 (modern) (modern) | starting rating: 1466 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 544 | Sewell, Matthew (1644) | Won 2-0 | +211487 |
| 2modern | 556 | Hwang, Jay (1539) | Lost 0-2 | -171470 |
| top | average opponent: 1591record: 1-1 | new rating: 1470 | ||
| Grand Prix Phoenix 2018 (modern) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 8 | Smith, Garrison (1500) | Lost 0-2 | -181482 |
| 2modern | 473 | McKeown, Zach (1482) | Lost 0-2 | -181464 |
| 3modern | 571 | Henberger, Gail (1573) | Lost 1-2 | -161448 |
| 4modern | 617 | Carlson, Michael (1400) | Won 2-0 | +171465 |
| 5modern | 572 | Stoker, Tyler (1468) | Lost 0-1 | -181447 |
| 6modern | 499 | Hounslow, Matthew (1434) | Won 2-0 | +181465 |
| 7modern | 389 | Chambers, Colron (1365) | Won 2-0 | +161481 |
| 8modern | 299 | Dell, Preston (1628) | Lost 0-2 | -151466 |
| top | average opponent: 1481record: 3-5 | new rating: 1466 | ||