Grinnell, Jeffrey
Current rating: 1510
Record: 15-14-1
| Grand Prix Pittsburgh 2013 (GTC limited) | starting rating: 1547 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 338 | Whiteman, Justin (1418) | Lost 0-2 | -201527 |
| 2sealed | 403 | Maynard, Jacob (1704) | Lost 1-2 | -151512 |
| 3sealed | 629 | Koontz, Brent M (1465) | Lost 1-2 | -191493 |
| 4sealed | 692 | Zahner, Christian H (1445) | Won 2-0 | +171510 |
| top | average opponent: 1508record: 1-3 | new rating: 1510 | ||
| Grand Prix Indianapolis 2013 (RTR limited) | starting rating: 1532 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 128 | Phipps, Dustin (1500) | Won 2-0 | +171549 |
| 2sealed | 95 | Edler, Jerry (1518) | Lost 1-2 | -181531 |
| 3sealed | 248 | Bohnhoff, Benjamin (1513) | Lost 1-2 | -181513 |
| 4sealed | 314 | Kress, Steve L (1489) | Won 2-0 | +171530 |
| 5sealed | 306 | Duncan, Christian (1498) | Lost 1-2 | -181512 |
| 6sealed | 276 | Scott, Zachary (1486) | Won 2-0 | +171529 |
| 7sealed | 203 | Levy, Adam (1577) | Lost 0-2 | -171512 |
| 8sealed | 208 | Li, Kai (1486) | Won 2-1 | +171529 |
| 9sealed | 168 | Majors, Brandon (1508) | Won 2-0 | +181547 |
| top | average opponent: 1508record: 5-4 | new rating: 1547 | ||
| Grand Prix Boston 2009 (M10 limited) | starting rating: 1518 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 472 | Wilson, Anthony (1434) | Won 2-1 | +171535 |
| 2sealed | 481 | Frier, Dov (1518) | Won 2-1 | +181553 |
| 3sealed | 432 | Chafe, Nathaniel (1483) | Lost 0-2 | -201533 |
| 4sealed | 623 | Lynk, John (1521) | Won 2-0 | +181551 |
| 5sealed | 477 | Healy, Jason (1486) | Lost 1-2 | -191532 |
| 6sealed | 591 | Blaskey, Chris (1514) | Won 2-0 | +181550 |
| 7sealed | 484 | Sprowls, Brandon (1593) | Lost 1-2 | -181532 |
| 8sealed | 507 | Darran, Jeff (1534) | Lost 1-2 | -181514 |
| 9sealed | 489 | Smelly, Robert (1498) | Won 2-1 | +181532 |
| top | average opponent: 1509record: 5-4 | new rating: 1532 | ||
| Grand Prix Detroit 2005 (BOK limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 42 | Zambrano, Carlos (1537) | Lost 1-2 | -171483 |
| 2sealed | 144 | Schue, David (1482) | Draw 1-1 | 01483 |
| 3sealed | 181 | Poljanac, Matthew (1486) | Lost 0-2 | -181465 |
| 4sealed | 214 | Freeman, Shawn (1463) | Won 2-0 | +181483 |
| 5sealed | 177 | Wcisel, Jim (1483) | Won 2-0 | +181501 |
| 6sealed | 133 | Jacobs, Joshua (1502) | Won 2-0 | +181519 |
| 7sealed | 101 | Tzaneteas, Elliott (1502) | Lost 0-2 | -191500 |
| 8sealed | 89 | Leong, Francis (1498) | Won 2-0 | +181518 |
| top | average opponent: 1494record: 4-3-1 | new rating: 1518 | ||