Simpson, Marshall
Current rating: 1513
Record: 28-31-1
| Grand Prix Las Vegas 2019 (modern) (modern) | starting rating: 1497 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 481 | Dubois, Seth (1429) | Won 2-1 | +171514 |
| 2modern | 389 | Haker, Elizabeth (1401) | Lost 1-2 | -201494 |
| 3modern | 438 | Cortez, Nestor (1503) | Won 2-1 | +181512 |
| 4modern | 368 | Bakker, Jonathan (1456) | Won 2-1 | +171529 |
| 5modern | 292 | LaPorte, Jordan (1492) | Won 2-1 | +171546 |
| 6modern | 74 | Burns-Kirkness, Rowan (1690) | Lost 0-2 | -151531 |
| 7modern | 355 | Wulterkens, Ben (1528) | Lost 0-2 | -181513 |
| top | average opponent: 1500record: 4-3 | new rating: 1513 | ||
| Grand Prix Dallas-Fort Worth 2018 (DOM limited) | starting rating: 1507 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 213 | Ditto, Ryan (1500) | Won 2-0 | +181525 |
| 2sealed | 23 | Fernandez, Christopher (1509) | Lost 0-2 | -181507 |
| 3sealed | 309 | Blubaugh, Paul (1457) | Won 1-0 | +171524 |
| 4sealed | 257 | Sikkink Johnson, Matt (1947) | Lost 1-2 | -111513 |
| 5sealed | 395 | Cotter, Andrew (1597) | Lost 1-2 | -161497 |
| top | average opponent: 1602record: 2-3 | new rating: 1497 | ||
| Grand Prix Las Vegas 2017 (limited) (AKH limited) | starting rating: 1433 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 703 | Nickolai, Matthew (1553) | Lost 1-2 | -161417 |
| 2sealed | 835 | Hudgens, Wade (1502) | Lost 1-2 | -161401 |
| 3sealed | 1107 | O'Connor, Kathleen (1464) | Won 2-0 | +191420 |
| 4sealed | 969 | Colgan, Matt (1539) | Won 2-0 | +201440 |
| 5sealed | 610 | Zuniga, Joe (1468) | Won 2-1 | +191459 |
| 6sealed | 523 | Sparks, Jesse (1527) | Won 2-1 | +191478 |
| 7sealed | 422 | Good, Mark (1634) | Won 2-1 | +211499 |
| 8sealed | 138 | Hallock, Jason (1540) | Lost 0-2 | -181481 |
| 9sealed | 358 | Miles, Julian (1547) | Won 2-1 | +201501 |
| 10draft | 143 | Chan, Royal (1559) | Won 2-0 | +191520 |
| 11draft | 127 | Ranco, Eric (1577) | Won 2-0 | +191539 |
| 12draft | 115 | Iiams, Brandon (1596) | Lost 1-2 | -171522 |
| 13draft | 107 | Wang, Charlie (1596) | Lost 0-2 | -171505 |
| 14draft | 125 | Boone, Zac (1524) | Won 2-0 | +181523 |
| 15draft | 42 | Nguyen, Thanh (1638) | Lost 0-2 | -161507 |
| top | average opponent: 1551record: 9-6 | new rating: 1507 | ||
| Grand Prix Dallas-Fort Worth 2016 (modern) | starting rating: 1455 | |||
| round | table | opponent (rating) | result | Δrating |
| 3modern | 112 | Stover, Harrison (1536) | Won 2-1 | +201475 |
| 4modern | 51 | Bosserman, Alexander (1707) | Lost 1-2 | -141461 |
| 5modern | 132 | Hayes, Carver (1535) | Lost 1-2 | -171444 |
| 6modern | 515 | Franklin, Lance (1648) | Lost 1-2 | -141430 |
| 7modern | 587 | Flint, David (1550) | Won 2-0 | +201450 |
| 8modern | 399 | King, Hannah (1500) | Lost 0-2 | -171433 |
| top | average opponent: 1579record: 2-4 | new rating: 1433 | ||
| Grand Prix Houston 2016 (OGW standard) | starting rating: 1420 | |||
| round | table | opponent (rating) | result | Δrating |
| 2standard | 354 | Crouse, Sean (1489) | Lost 1-2 | -161404 |
| 3standard | 397 | Sommerfeld, Daniel (1487) | Lost 1-2 | -171387 |
| 4standard | 726 | Russell, David M (1394) | Won 2-0 | +181405 |
| 5standard | 553 | Canavati, Andreas (1811) | Draw 1-1 | +71412 |
| 6standard | 532 | Nichols, Jordan (1499) | Won 2-1 | +201432 |
| 7standard | 401 | Bosworth, James (1464) | Won 2-1 | +181450 |
| 8standard | 272 | Cullerton, Evan (1614) | Won 2-1 | +211471 |
| 9standard | 186 | Hill, Andrew (1576) | Lost 0-2 | -161455 |
| top | average opponent: 1542record: 4-3-1 | new rating: 1455 | ||
| Grand Prix Oklahoma City 2015 (modern) | starting rating: 1469 | |||
| round | table | opponent (rating) | result | Δrating |
| 2modern | 44 | Smith, Sean (1718) | Lost 1-2 | -141455 |
| 3modern | 357 | Callison, Justin (1502) | Lost 0-0 | -171438 |
| 4modern | 416 | Saindon, Blake (1444) | Lost 0-2 | -181420 |
| 5modern | 497 | Steinbrink, Brett (1464) | Won 2-0 | +191439 |
| 6modern | 402 | Gooch, Josh (1400) | Lost 0-2 | -191420 |
| top | average opponent: 1506record: 1-4 | new rating: 1420 | ||
| Grand Prix Las Vegas 2015 (2) (MM2 limited) | starting rating: 1459 | |||
| round | table | opponent (rating) | result | Δrating |
| 2sealed | 12 | Sanchez, Kyle (1766) | Lost 0-2 | -131446 |
| 3sealed | 288 | Park, Larry (1469) | Won 2-0 | +191465 |
| 4sealed | 146 | Hill, Vincent (1505) | Lost 1-2 | -181447 |
| 5sealed | 198 | Ma, Anan (1524) | Lost 1-2 | -161431 |
| 6sealed | 194 | Baucom, Camrin (1481) | Won 2-0 | +191450 |
| 7sealed | 154 | Johnson, Brandon (1462) | Won 2-1 | +181468 |
| 8sealed | 100 | Colton, William (1471) | Lost 0-2 | -181450 |
| 9sealed | 89 | Monay, Mark Bryan (1498) | Won 2-0 | +191469 |
| top | average opponent: 1522record: 4-4 | new rating: 1469 | ||
| Grand Prix San Antonio 2014 (KTK standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 110 | Luster, Patrick (1370) | Lost 0-2 | -201480 |
| 2standard | 490 | Peters, David (1415) | Won 2-0 | +161496 |
| 3standard | 305 | Litton, Jonathan (1401) | Won 2-0 | +171513 |
| 4standard | 179 | Heath, Joel (1520) | Lost 0-2 | -181495 |
| 5standard | 325 | Luera, Mike (1499) | Lost 0-2 | -181477 |
| 6standard | 328 | Lopez, Joshua (1466) | Lost 0-2 | -181459 |
| top | average opponent: 1445record: 2-4 | new rating: 1459 | ||