1.Qa5? thraet: 2.Be6 f4 3.Qd5+ Kc3 4.Qd2#

2...Kd3 3.Qd2+ Ke4 4.Qe3#

2...Ke4 2.Qd5 Kf4 4.Qf5#

but: 1...Ke5!

1.Be6?

1...Kc5 2.Qa5+ Kd4 3.Qd5+ Kc3 4.Qd2#

2...Kd6 3.Bc4 threat: 4.Qc7#

3...Ke7 4.Qd8#

2...Kc6 3.Bc4 threat 4.Qc7#

but: 1...Ke5!

1.Kc7?/ Kd7?, Ke5!

1.Bf7!

1...Ke5 2.Qe6+ Kf4 3.Qe3+ Kg4 4.Qg3#

1...Kc5 2.Qa5+ Kd4 3.Qd5+ Kc3 4.Qd2#

2...Kc6 3.Bc4 threat: 4.Qc7#

1...Ke4 2.Qe2+ Kf4 3.Qe3+ Kg4 4.Qg3#

thema BRISTOL

b)

1.Kc7?/ Be6?/ Ba2?/, Ke5!, Ke5!

1.Bf7!

1...Ke5 2.Qe7+ Kf4 3.Qe3+ Kg4 4.Qg3#

1...Kc5 2.Kc7 Kd4 3.Qd5+ Kc3 4.Qd2#

1...Kd3 2.Qg2 threat: 3.Qd2+ Ke4 4.Qe3#

2...Kd4 3.Qd5+ Kc3 4.Qd2#

( 1...Kc3 2.Qb3+ Kd4 3.Qe3# )

comment: same key, a completly different game a

and b.