Rb4 ... c5xRb4 ... Qc8#
Rb4 ... a6 ... Qxa6#
Rb4 ... e5 ... Qd5#
Rb4 ... f4 ... Qe4#

nostr:nevent1qqsrtqn8rs2wrsgcmc5jw9nvgxhqjn80r5kza89nr33sa0sqejsa4dspz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsygzg0vuqauxq65fps8anr35w4zy6wtjyh5hus4dq9apdqvguknhk0vpsgqqqqqqs7vq0mv