Johnston, Mark
Current rating: 1469
Record: 4-7
| Grand Prix Los Angeles 2018 (M19 standard) | starting rating: 1499 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 177 | Morris, Seth (1500) | Lost 1-2 | -181481 |
| 2standard | 301 | Soth, Eric (1782) | Lost 1-2 | -121469 |
| average opponent: 1641record: 0-2 | new rating: 1469 | |||
| Grand Prix Portland 2016 (EMN standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 3standard | 255 | Bennison, Andrew (1522) | Won 2-1 | +181518 |
| 4standard | 84 | Joyaux, Daniel (1555) | Won 2-0 | +191537 |
| 5standard | 79 | Stroud, David (1820) | Lost 0-2 | -131524 |
| 6standard | 134 | Patrick-Riley, Josh (1595) | Won 2-0 | +191543 |
| 7standard | 111 | Bruggman, Beaux (1620) | Lost 1-2 | -161527 |
| 8standard | 202 | Sellers, Josh (1649) | Won 2-0 | +201547 |
| 9standard | 102 | Huteson, Tom (1743) | Lost 0-0 | -141533 |
| 10standard | 178 | Boston, Steven (1563) | Lost 0-2 | -181515 |
| 11standard | 176 | Page, Jonathan (1635) | Lost 0-2 | -161499 |
| average opponent: 1634record: 4-5 | new rating: 1499 | |||