6 -
Probleemblad, 2000
16+10. Beweispartie in 6.5 Zügen
[1n2kbnr/2p1pppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR]
1. e4 a6 2. Ba6 d5 3. Bb7 Ra6 4. Bd5 Bb7 5. Bb7 Qd3 6. Ba6 Qf1 7. Bf1
Under one reasonable way to define switchbacks, there are three here, all with captures on the return moves.