Hefferle, Stephen
Current rating: 1487
| Grand Prix Hartford 2018 (modern) | starting rating: 1517 | |||
| round | table | opponent (rating) | result | Δrating |
| 2modern | 282 | Lerch, Kyle (1526) | Won 2-0 | +191536 |
| 3modern | 235 | Buchanan, Jessica (1784) | Lost 0-2 | -141522 |
| 4modern | 446 | Rosol, Benjamin (1521) | Lost 1-2 | -181504 |
| 5modern | 593 | Kesilewski, Stanley (1579) | Lost 1-2 | -171487 |
| 6modern | 602 | Streeter, Rebecca (1473) | Won 2-0 | +181505 |
| 7modern | 501 | Kugler, Matt (1506) | Lost 0-2 | -181487 |
| top | average opponent: 1565record: 2-4 | new rating: 1487 | ||
| Grand Prix Pittsburgh 2015 (modern) | starting rating: 1520 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 754 | Stopansky, Joe (1500) | Won 2-0 | +171537 |
| 2modern | 348 | Long, Kerrick (1518) | Lost 1-2 | -181519 |
| 3modern | 1056 | Jarvis, Jamie (1484) | Lost 0-2 | -191500 |
| 4modern | 1103 | Balyszak, James (1448) | Won 2-0 | +171517 |
| 5modern | 751 | Schryver, Kyle (1602) | Won 2-0 | +201537 |
| 6modern | 417 | Campman, Andrew (1452) | Lost 1-2 | -201517 |
| top | average opponent: 1501record: 3-3 | new rating: 1517 | ||
| Grand Prix New Jersey 2014 (legacy) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 394 | Downey, Ken (1460) | Lost 0-2 | -191481 |
| 2legacy | 478 | Ford, Francis (1482) | Won 2-0 | +181499 |
| 3legacy | 337 | Newman, Michael (1552) | Lost 0-2 | -171482 |
| 4legacy | 503 | Adamy, Jason (1484) | Won 2-0 | +181500 |
| 5legacy | 441 | Song, Jungin (1419) | Won 2-0 | +171517 |
| 6legacy | 340 | Sudendorf, Vanessa (1511) | Won 2-0 | +181535 |
| 7legacy | 265 | Green, Benjamin (1706) | Lost 0-2 | -151520 |
| top | average opponent: 1516record: 4-3 | new rating: 1520 | ||