Answer: 30...Rf1+ as played in the game and White resigned before 31.Kxf1 Ne3+ 32.Rxe3 Bxb3 33.Re1 Bxa2
Alternative Answer–by computer suggestion: 30...Qe7 31.Qc2 Rh1 32.Qe2 Qh4+ 33.g3 Qxh3 34.Qe6+ Qxe6 35.Kg2 Qe2+ 36.Kxh1 Qxd3 37.Kg1 Qxf3 38.b3 Qg2#
Answer to chess study:
In response to 29.Bxd8, Black played 29...Bf5 30.a4 Qd7 and White resigned in view of 31.Rc7 Qe6 and the White Queen is trapped.
White's only resource 29.a4 first, preventing Qd7 as the Bishop has not yet played Bf5. Sample line is 29.a4 Qh5 30.Qxh5 Rxh5 31.Bxd8 Bc6.
Click this link if you can not see the complete game below:
http://mid-southchessadvocate.blogspot.com/2021/08/white-david-phillips-black-graham.html
