2017 Michigan Open
5 • IM jposthuma •- Joshua Posthuma (2315) - Gregory Bailey (1903)
- Joshua Posthuma (2315) - Eric Li (1944)
- Andrew Schremser (2010) - Joshua Posthuma (2315)
- Jason Zheng (1923) - Joshua Posthuma (2315)
- IM jposthuma
2017 Supernationals Games
11 • IM jposthuma •- Joshua Posthuma (2317) - Prateek Pinisetti (2133) 1-0
- Eric Hon (2058) - Joshua Posthuma (2317) 0-1
- Joshua Posthuma (2317) - Rochelle Wu (2082) 1-0
- IM Kesav Viswanadha (2458) - Joshua Posthuma (2317) 1-0
- IM jposthuma
My 2021 National Open Games
6 • IM jposthuma •- Ronald Allen (Unr) - FM Joshua Posthuma (2256)
- FM Joshua Posthuma (2256) - GM Titas Stremavicius (2469)
- GM Pavlo Varontsov (2540) - FM Joshua Posthuma (2256)
- GM Steven Zierk (2499) - FM Joshua Posthuma (2256)
- IM jposthuma
- EnPassant81
- NM self_service
2017 Michigan Class Championship Games
3 • IM jposthuma •- Joshua Posthuma (2255) - Manis Davidovich (2229) WIN
- Joshua Posthuma (2255) - Justin Liang (2039) WIN
- Alexander Deatrick (2136) - Joshua Posthuma (2255) DRAW
- Mark Heimann (2440) - Joshua Posthuma (2255) DRAW
- IM jposthuma
- NM mn8
- NM upandcomer
My Indianapolis Open Games
1 • IM jposthuma •- Glenn Snow (2027) - Joshua Posthuma (2314)
- Iris Zhou (1904) - Joshua Posthuma (2314)
- Joshua Posthuma (2314) - Brian Yang (1993)
- Joshua Posthuma (2314) - Priyadharshan Kannappan (2593)
- IM jposthuma
Matthew Lesson 10/5/2023 - Open Sicilian Plans
1 • IM jposthuma •- Najdorf Type 2
- #1
- #2
- #3
- IM jposthuma
- walkingegg
2017 Chicago Open
9 • IM jposthuma •- GM Ruifeng Li (2574) - Joshua Posthuma (2268)
- Joshua Posthuma (2268) - FM Arthur Guo (2122)
- Joshua Posthuma (2268) - Steve Wongso (1636)
- IM Michael Song (2423) - Joshua Posthuma (2268)
- IM jposthuma