Without Sd1 or without Lb1 White could play
1. Df2+ gxf2++.
1. Se3? (2. Df2+) Txb1!
1. La2, Lc2, Ld3? (2. Df2+) T(x)a2!/Txd1!

1. Td4! (2. Le4+ Kf4 3. Sh7+ Kxe5 4. Te7+ Kf4
5. Ld3+/Lc2+ > identical motive: keeping Sd1 pinned!
5. - Kf3 6. Df2+) Tb6?/Tb7?/Txe5?/Lxg6?
2. Sxg4+ Tf6/Txf7/Tf5/Lxf7, Lf5 3. Sxh2+ D/gxh2++.
1. - Td5! (5. - Txd4!)
2. Se3! (3. Df2+) Txb1
3. Sxd5? (4. Dd1+ Txd1++) Td1!
3. Sd1!!, Switchback (4. Df2+) Txb2? 4. Sxb2! ~ 5. Df2+.
3. - Txd1!
4. Tf4+! Kxf4
5. Se4+ Kxe5
6. Sf2+! Txe1++.

Sideline:
1. - Dh4
2. Sd5+/Sxh5+ > identical motive: guarding f4! Df6
3. Se3 (4. Tf4+ Dxf4 5. Df2+) Txb1
4. Sxg4! The short threat (5. Dd1+) is eliminated by Td1,
but the longer one succeeds:
5. Tf4+ Dxf4
6. Sh2+ gxh2++.