1. Sa3? Kf1 2. Sc2 Kg1 3. Ke2 Kg2 4. Se1+ Kg1 5. Sd3 Kg2 6. Sdf4+ transposes to main line of try
4. ... Rxe1+!

4. Se3+ Kg1 5. Sd5 Kg2 6. Sdf4+ Kg1 7. Sxh3+ Kg2 8. S3f4+ Kg1 9. Kf3 Kf1 10. Sg2 Kg1 11. Shf4 Kf1 12. Se2 Rg1 13. Sg3#

2. ... Rg1!

1. Sf4! Kf1 2. Sd3 Kg1 3. Sc3 Kf1 4. Se4 Kg1 5. Ke2 Kg2 6. Sf4+ Kg1 7. Sxh3+ Kg2 8. Sf4+ Kg1 9. Kf3 Kf1 10. Sg2 Kg1 11. Sg3? stalemate!

11. Sc3 Kf1 12. Se2 Rg1 13. Sg3#

Keywords: exchange of roles (SS over the full stipulation length), White correction, stalemate avoidance, double k-pendulum (g1-f1/g2), switchback (KSk,KSSk) , selfblock, square vacation, line closing (g1-g3), changed continuations (on 1. ... Kf1), annihilation (bPh3), meredith (gravure)