Zack, Michael
Current rating: 1415
| Grand Prix Atlanta 2018 (modern) | starting rating: 1432 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 93 | Lee, Michael 4581 (1500) | Lost 0-2 | -171415 |
| top | record: 0-1 | new rating: 1415 | ||
| Grand Prix Richmond 2014 (modern) | starting rating: 1446 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 1121 | Lo, William (1482) | Lost 1-2 | -171429 |
| 2modern | 1422 | Valiente, Alvaro (1482) | Won 2-0 | +191448 |
| 3modern | 1450 | Howard, Duncan (1460) | Lost 1-2 | -181430 |
| 4modern | 1595 | Gekoskie, Nicholas (1484) | Won 2-0 | +191449 |
| 5modern | 1445 | Currie, Matthew (1514) | Lost 0-2 | -171432 |
| top | average opponent: 1484record: 2-3 | new rating: 1432 | ||
| Grand Prix Pittsburgh 2013 (GTC limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 308 | Montanaro, John (1500) | Lost 1-2 | -181482 |
| 2sealed | 474 | VanCleve, Matt (1482) | Lost 0-2 | -181464 |
| 3sealed | 654 | Belknap, Amber (1466) | Lost 1-2 | -181446 |
| top | average opponent: 1483record: 0-3 | new rating: 1446 | ||