Grosteffon, Josh
Current rating: 1645
Record: 37-32
| Grand Prix Louisville 2017 (legacy) | starting rating: 1690 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 336 | Burton, Cody (1686) | Lost 1-2 | -181672 |
| 2legacy | 725 | Newton, Kegan (1555) | Lost 1-2 | -201652 |
| 3legacy | 1023 | Weaver, Josh (1461) | Won 2-0 | +141666 |
| 4legacy | 1005 | Davis, Mark (1483) | Lost 0-2 | -211645 |
| top | average opponent: 1546record: 1-3 | new rating: 1645 | ||
| Grand Prix Indianapolis 2016 (modern) | starting rating: 1552 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 281 | Nyberg, Michael (1942) | Won 2-1 | +251577 |
| 2modern | 256 | Rodaitis, Andrew (1511) | Won 2-1 | +171594 |
| 3modern | 20 | Wolf, Logan (1634) | Lost 1-2 | -171577 |
| 4modern | 600 | Schlegel, Thomas (1657) | Won 2-0 | +191596 |
| 5modern | 424 | Lauerman, James (1552) | Won 2-1 | +171613 |
| 6modern | 119 | Lopez, Chris (1811) | Won 2-0 | +221635 |
| 7modern | 133 | Lucas, Keith (1570) | Won 2-1 | +171652 |
| 8modern | 60 | Hileman, Devin (1604) | Won 2-0 | +171669 |
| 9modern | 18 | Riggs, Eric (1535) | Lost 0-2 | -211648 |
| 10modern | 928 | Cathro, Daniel (1803) | Won 2-1 | +211669 |
| 11modern | 867 | Lee, Brian (1791) | Lost 1-2 | -161653 |
| 12modern | 903 | Coleman, Allison (1727) | Won 2-1 | +201673 |
| 13modern | 914 | Harmon, Lawrence (1661) | Lost 0-2 | -181655 |
| 14modern | 952 | Eaton, Cameron (1656) | Won 2-1 | +181673 |
| 15modern | 890 | Davis, Justin (1640) | Won 2-1 | +171690 |
| top | average opponent: 1673record: 11-4 | new rating: 1690 | ||
| Grand Prix Columbus 2016 (legacy) | starting rating: 1513 | |||
| round | table | opponent (rating) | result | Δrating |
| 3legacy | 372 | Hare, Ryan (1767) | Won 2-0 | +231536 |
| 4legacy | 44 | Mcclain, Josh (2051) | Won 2-0 | +271563 |
| 5legacy | 100 | Hamilton, George (1497) | Won 2-0 | +161579 |
| 6legacy | 31 | Johnson, James (1502) | Lost 0-2 | -191560 |
| 7legacy | 62 | Musick, Joel (1621) | Lost 0-2 | -171543 |
| 8legacy | 153 | Bashaar, Charles (1576) | Lost 1-2 | -171526 |
| 9legacy | 285 | Hillaker, John (1540) | Won 2-0 | +181544 |
| 10legacy | 147 | Mollenkopf, Tyler (1550) | Lost 1-2 | -181526 |
| 11legacy | 206 | Krasnozon, Jefferey (1570) | Won 2-0 | +191545 |
| 12legacy | 151 | Lowther, Evan (1600) | Won 2-0 | +191564 |
| 13legacy | 101 | Dennis, Matthew (1682) | Won 2-1 | +201584 |
| 14legacy | 63 | Accetturo, Vince (1647) | Lost 1-2 | -171567 |
| 15legacy | 117 | Elsik, Zac (1746) | Lost 0-2 | -151552 |
| top | average opponent: 1642record: 7-6 | new rating: 1552 | ||
| Grand Prix Detroit 2016 (modern) | starting rating: 1468 | |||
| round | table | opponent (rating) | result | Δrating |
| 3modern | 60 | Herrell, Justin (1788) | Won 2-0 | +231491 |
| 4modern | 135 | Kidd, Brandon (1641) | Won 2-0 | +211512 |
| 5modern | 47 | Bohn, Jonathan (1597) | Lost 1-2 | -171495 |
| 6modern | 233 | Timmerman, Trace (1551) | Won 2-0 | +191514 |
| 7modern | 89 | Collier, Joshua (1511) | Lost 1-2 | -181496 |
| 8modern | 301 | Wilson, Richard M (1605) | Won 2-0 | +201516 |
| 9modern | 113 | Wilbanks, Clayton (1591) | Won 2-1 | +201536 |
| 10modern | 58 | Kassis, Eli (1887) | Lost 0-2 | -121524 |
| 11modern | 152 | Howitt, Josh (1724) | Won 2-0 | +211545 |
| 12modern | 80 | Cavin, Will (1597) | Lost 1-2 | -171528 |
| 13modern | 170 | Rong, Kei (1697) | Lost 1-2 | -151513 |
| top | average opponent: 1654record: 6-5 | new rating: 1513 | ||
| Grand Prix Charlotte 2015 (modern) | starting rating: 1486 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 985 | Gainey, Cory M (1500) | Lost 0-2 | -171469 |
| 2modern | 1061 | Phipps, Neil (1481) | Won 2-0 | +181487 |
| 3modern | 914 | Skoler, Alex (1483) | Lost 1-2 | -181469 |
| 4modern | 1065 | Johnny, Jonathan M (1482) | Won 2-1 | +181487 |
| 5modern | 883 | Keller, Chris (1403) | Lost 1-2 | -191468 |
| top | average opponent: 1470record: 2-3 | new rating: 1468 | ||
| Grand Prix Cleveland 2015 (FRF limited) | starting rating: 1504 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 166 | Gold, Gary (1517) | Lost 0-2 | -171487 |
| 2sealed | 637 | Burnett, William (1482) | Won 2-0 | +181505 |
| 3sealed | 490 | Sutyak, Cory (1498) | Lost 0-2 | -191486 |
| top | average opponent: 1499record: 1-2 | new rating: 1486 | ||
| Grand Prix New Jersey 2014 (legacy) | starting rating: 1482 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 389 | Owens, Andrew (1500) | Won 2-0 | +181500 |
| 2legacy | 136 | Shiver, Michael (1504) | Lost 0-2 | -181482 |
| 3legacy | 498 | Vogt, Mark (1516) | Won 2-1 | +191501 |
| 4legacy | 251 | Bullington, Jay (1635) | Lost 1-2 | -161485 |
| 5legacy | 375 | Gibson, Michael (1508) | Won 2-1 | +191504 |
| 6legacy | 283 | Gritz, Daniel (1520) | Won 2-1 | +181522 |
| 7legacy | 255 | Hayden-Rowe, Stefan (1541) | Lost 1-2 | -181504 |
| top | average opponent: 1532record: 4-3 | new rating: 1504 | ||
| Grand Prix Detroit 2013 (modern) | starting rating: 1501 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 346 | Holloway, Robert (1500) | Won 2-1 | +181519 |
| 2modern | 36 | Santchi, Colton (1518) | Won 0-0 | +181537 |
| 3modern | 189 | Douglass, John (1516) | Lost 0-2 | -181519 |
| 4modern | 413 | De Pinho, Jonathan (1509) | Lost 1-2 | -191500 |
| 5modern | 516 | Olszowy, John h (1473) | Lost 0-2 | -181482 |
| top | average opponent: 1503record: 2-3 | new rating: 1482 | ||
| Grand Prix Charlotte 2013 (GTC limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 87 | Tuten, Thomas (1500) | Won 2-1 | +181518 |
| 2sealed | 215 | Tourloukis, Chris (1514) | Lost 1-2 | -181500 |
| 3sealed | 287 | Gottstein, Jeff (1530) | Lost 1-2 | -181482 |
| 4sealed | 407 | Osyda, Eric (1517) | Won 2-1 | +191501 |
| 5sealed | 400 | Franks, Karen (1500) | Won 2-1 | +181519 |
| 6sealed | 309 | McDaniel, Kyle (1514) | Lost 0-2 | -181501 |
| top | average opponent: 1512record: 3-3 | new rating: 1501 | ||