Halford, Joseph E
Current rating: 1435
Record: 11-16-1
| Grand Prix Oklahoma City 2013 (THS limited) | starting rating: 1446 | |||
| round | table | opponent (rating) | result | Δrating |
| 2sealed | 217 | Criminger, Blakely (1518) | Won 2-1 | +191465 |
| 3sealed | 292 | Montgomery, Stoney (1462) | Lost 0-2 | -181447 |
| 4sealed | 257 | Tegethoff, Ethan (1517) | Lost 1-2 | -171430 |
| 5sealed | 367 | Alcorn, Bryan (1512) | Won 2-0 | +201450 |
| 6sealed | 329 | Stefan, Isaiah (1517) | Won 2-0 | +191469 |
| 7sealed | 277 | Fischer, Brandon (1507) | Lost 0-2 | -171452 |
| 8sealed | 285 | Bullock, Jason (1506) | Lost 0-2 | -171435 |
| top | average opponent: 1506record: 3-4 | new rating: 1435 | ||
| Grand Prix Miami 2013 (DGM standard) | starting rating: 1456 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 173 | Toolan, Kevin (1500) | Won 2-0 | +181474 |
| 2standard | 72 | Perlman, David (1522) | Won 2-1 | +191493 |
| 3standard | 161 | Marich, Eric (1518) | Lost 0-2 | -171476 |
| 4standard | 208 | McMicheaux, Zach (1519) | Won 2-1 | +191495 |
| 5standard | 100 | Figueroa, Milton (1616) | Lost 1-2 | -161479 |
| 6standard | 355 | Vilain, Arnaud (1524) | Lost 1-2 | -171462 |
| 7standard | 293 | Lee, Alan 2 (1583) | Lost 1-2 | -161446 |
| top | average opponent: 1540record: 3-4 | new rating: 1446 | ||
| Grand Prix Atlanta 2012 (legacy) | starting rating: 1489 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 39 | Bankman-Fried, Sam (1602) | Lost 0-2 | -161473 |
| 2legacy | 282 | Comminos, Steven (1461) | Draw 1-1 | 01473 |
| 3legacy | 314 | Joubert, Hillary (1563) | Lost 1-2 | -161457 |
| 4legacy | 419 | Solorzano, Nephi (1413) | Won 2-1 | +171474 |
| 5legacy | 373 | Waechter, Kurt (1413) | Won 2-1 | +171491 |
| 6legacy | 304 | Ardary, Steven (1501) | Lost 0-2 | -181473 |
| 7legacy | 314 | Hiller, Ryan (1481) | Lost 1-2 | -181455 |
| 8legacy | 286 | Landa, Diego (1462) | Won 2-0 | +181473 |
| 9legacy | 245 | Howell, Michael (1495) | Lost 0-2 | -171456 |
| top | average opponent: 1488record: 3-5-1 | new rating: 1456 | ||
| Grand Prix Kansas City 2011 (NPH limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 214 | Bailey, Phillip (1500) | Won 2-1 | +181518 |
| 2sealed | 214 | Mangner, Sean (1727) | Lost 0-2 | -141504 |
| 3sealed | 307 | Dixson, Tim (1555) | Lost 0-2 | -171487 |
| 4sealed | 355 | Guilbault, Kelvin (1482) | Won 2-1 | +181505 |
| 5sealed | 305 | Prabhu, Vinnie (1646) | Lost 0-2 | -161489 |
| top | average opponent: 1582record: 2-3 | new rating: 1489 | ||