[4] He was studying data science until December 2021, before deciding to drop out of college during the first year to focus on his chess career.

[7] 2021 was a strong year for Arjun Erigaisi, as he became the first Indian to qualify to the Goldmoney Asian Rapid of the Champions Chess Tour 2021[8] ahead of Alireza Firouzja, Daniil Dubov, Peter Svidler and Vidit Gujrathi, only losing to Levon Aronian in tie breaks in a hard-fought match.

[9] In October 2021, Arjun placed 2nd at the Junior U21 Round Table Open Chess Championship (Classical) held in Bulgaria.

[10] In November 2021, Arjun placed 3rd/82 in the Lindores Abbey Blitz Tournament at Riga ahead of players such as Maxime Vachier-Lagrave, Levon Aronian, David Navara, Daniil Dubov, Peter Svidler and many others.

He scored 6.5/9, ahead of Vidit Gujrathi, Levon Aronian, Sam Shankland and Lê Quang Liêm.

[21] In October 2024, Arjun won the 2024 WR Chess Masters Cup in London by defeating Maxime Vachier-Lagrave in an armageddon tiebreak in the final.