Codman, John
Current rating: 1508
Record: 18-18-1
| Grand Prix New Jersey 2014 (legacy) | starting rating: 1523 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 215 | Nickerson, Craig (1500) | Won 2-0 | +171540 |
| 2legacy | 206 | Hayward, Tom (1401) | Won 2-0 | +161556 |
| 3legacy | 229 | Ulanov, Denis (2026) | Lost 0-2 | -101546 |
| 4legacy | 244 | O'Dell, Roy (1462) | Lost 0-2 | -201526 |
| 5legacy | 340 | Smolinski, Kenneth (1499) | Lost 1-2 | -181508 |
| top | average opponent: 1578record: 2-3 | new rating: 1508 | ||
| Grand Prix Washington DC 2014 (JOU limited) | starting rating: 1526 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 31 | Deacon, Shaun (1555) | Lost 1-2 | -181508 |
| 2sealed | 356 | Johnson, Jimmie (1464) | Won 2-1 | +181526 |
| 3sealed | 396 | LeClair, Greg (1492) | Won 2-0 | +171543 |
| 4sealed | 349 | Feng, Feng (1392) | Lost 0-2 | -211522 |
| 5sealed | 370 | Espejo, Jonny (1494) | Won 2-1 | +181540 |
| 6sealed | 243 | Kukla, Nick (1587) | Lost 0-2 | -171523 |
| top | average opponent: 1497record: 3-3 | new rating: 1523 | ||
| Grand Prix Richmond 2014 (modern) | starting rating: 1509 | |||
| round | table | opponent (rating) | result | Δrating |
| 2modern | 32 | Telkamp, Matthias Paul (1488) | Lost 0-2 | -181491 |
| 3modern | 394 | Copenhaver, Eric (1578) | Won 2-0 | +201511 |
| 4modern | 318 | Seiber, Alex (1520) | Won 2-0 | +181529 |
| 5modern | 168 | Madden, Christine (1485) | Won 2-0 | +171546 |
| 6modern | 143 | Groen, Joshua (1484) | Draw 1-1 | -11545 |
| 7modern | 127 | Collins, Eric (1494) | Lost 0-2 | -191526 |
| top | average opponent: 1508record: 3-2-1 | new rating: 1526 | ||
| Grand Prix Washington DC 2013 (legacy) | starting rating: 1527 | |||
| round | table | opponent (rating) | result | Δrating |
| 3legacy | 108 | Rose, Phil (1477) | Won 2-0 | +171544 |
| 4legacy | 7 | Cornwell-Shiel, Chris (1482) | Lost 0-2 | -191525 |
| 5legacy | 74 | Wilburn, Aaron (1566) | Lost 1-2 | -171508 |
| 6legacy | 413 | Albergo, Patrick (1644) | Lost 1-2 | -161492 |
| 7legacy | 264 | Kim, Jason (1540) | Lost 0-2 | -171475 |
| 8legacy | 408 | Westbrook, Matthew (1387) | Won 2-0 | +161491 |
| 9legacy | 321 | Cotner, Nathan (1487) | Won 2-1 | +181509 |
| top | average opponent: 1512record: 3-4 | new rating: 1509 | ||
| Grand Prix Boston-Worcester 2012 (M13 limited) | starting rating: 1483 | |||
| round | table | opponent (rating) | result | Δrating |
| 2sealed | 103 | Breitman, Alan (1452) | Lost 1-2 | -181465 |
| 3sealed | 487 | Rosoff, Michael (1501) | Won 2-0 | +181483 |
| 4sealed | 464 | Lavoie, Alex (1539) | Won 2-1 | +191502 |
| 5sealed | 139 | Remeika, John (1552) | Won 2-1 | +191521 |
| 6sealed | 243 | Smith, Joey J (1601) | Lost 1-2 | -161505 |
| 7sealed | 333 | Jackson, Nathaniel (1524) | Won 2-0 | +181523 |
| 8sealed | 150 | Cheung, Justin (1658) | Won 2-1 | +211544 |
| 9sealed | 89 | Doyle, Michael (1621) | Lost 1-2 | -171527 |
| top | average opponent: 1556record: 5-3 | new rating: 1527 | ||
| Grand Prix Melbourne 2012 (DKA limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 4sealed | 52 | Adams, Lewis (1555) | Lost 0-2 | -171483 |
| 5sealed | 67 | Muralitheran, Hari (1344) | Won 2-1 | +151498 |
| 6sealed | 28 | Spark, Benjamin (1542) | Lost 0-2 | -171481 |
| 7sealed | 89 | Sheehan, Anthony (1540) | Lost 1-2 | -171464 |
| 8sealed | 107 | Gao, Frank (1517) | Won 2-1 | +191483 |
| top | average opponent: 1500record: 2-3 | new rating: 1483 | ||