Kellogg, Zach
Current rating: 1441
| Grand Prix Detroit 2016 (modern) | starting rating: 1476 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 20 | Abbott, Alanna (1500) | Won 2-0 | +191495 |
| 2modern | 342 | Fryer, Tom (1497) | Lost 0-2 | -181477 |
| 3modern | 820 | Moore, Jordyn (1494) | Lost 0-2 | -181459 |
| 4modern | 853 | Strausman, Shea (1473) | Won 2-1 | +181477 |
| 5modern | 782 | Ski, Kendra (1500) | Lost 1-2 | -171460 |
| 6modern | 913 | Hallock, Jeremy (1438) | Lost 1-2 | -191441 |
| top | average opponent: 1484record: 2-4 | new rating: 1441 | ||
| Grand Prix Minneapolis 2014 (modern) | starting rating: 1489 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 709 | Adkins, Kyle (1500) | Lost 0-2 | -181471 |
| 2modern | 742 | Franks, Cameron (1490) | Lost 0-2 | -181453 |
| 3modern | 829 | Ebnet, Peter (1429) | Won 2-0 | +181471 |
| 4modern | 696 | Hedgpeth, Jordan (1448) | Won 2-1 | +171488 |
| 5modern | 668 | Wiedewitsch, Ryan (1484) | Won 2-1 | +181506 |
| 6modern | 471 | Meyer, Justin (1734) | Lost 0-2 | -141492 |
| 7modern | 467 | Caesar, David (1592) | Won 2-0 | +201512 |
| 8modern | 341 | Peterson, August (1518) | Lost 0-2 | -181494 |
| 9modern | 360 | Woodward, Jeremy (1499) | Lost 0-2 | -181476 |
| top | average opponent: 1522record: 4-5 | new rating: 1476 | ||
| Grand Prix Detroit 2013 (modern) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 411 | Robinson, Adam (1675) | Won 2-1 | +211521 |
| 2modern | 33 | Wilshire, Charles (1518) | Lost 0-0 | -181503 |
| 3modern | 559 | Hesik, Chris (1501) | Won 2-1 | +181521 |
| 4modern | 243 | Thompson, Kale (1596) | Lost 0-2 | -171504 |
| 5modern | 545 | Zavala, Alexander (1609) | Lost 1-2 | -161488 |
| 6modern | 497 | Foshe, Chris (1506) | Won 2-0 | +191507 |
| 7modern | 370 | Hill, Tyler (1500) | Lost 0-0 | -181489 |
| top | average opponent: 1558record: 3-4 | new rating: 1489 | ||