Starting out with one of my own which I think is quite nice. The key is obvious but does allow two checks. This has a definite theme: Karstrom-Fleck. The key makes 3 threats which are each individually forced and there are three total defenses. 1.Kc2! (2.Be2/Bd3/Bxc4) 1...Be2 2.Bxe2 1...Bd3+ 2.Bxd3 1...Ba6 2.Bc4 1...Bb3+ 2.axb3 1...Bd5 2.Bg2 1...Bxf2 2.Rxf2 Six mates, five of them with batteries, in a miniature. |

Here is a classic. The problem is a complete block: 1...B~ 2.Q(x)c2 1...S~ 2.Q(x)d2 1...c3 2.Qb5 The key gives a flight threatens a mate thus making it a block-threat. 1.Rg2! (>2.Qd4) 1...Ke3/c3 2.Qe2 1...Sd2 2.Qxd2 1...Sf2 2.Rg3 Two observations about this problem. First, it is a nice exercise to see why the wR has to go to g2 for the key instead of say h2. Second, it has a minor dual after 1...Sc3 2.Qd2/Rg3. |

Another classic from the great American composer. The key-piece is out-of-play but there changed mate, corner to corner wQ mates, Black correction, and accurate play. The wS could be a wP, but that is a matter of taste. 1.Ra7 (-) 1...Kxa2 2.Rxa6 1...B~ 2.Qh8 1...Bc8 2.Qa1 |

One good Shinkman deserves another. Composing in the early 1900 must have been nice when simple, neat ideas like this were still possible. Here the wR takes the LONG way around the board back to its original square. 1.Rh8 (>2.a8=Q) 1...Kxa7 2.Rxh1 Rb8 3.Ra1 Rc8 4.Ra8 |

Here is a beautiful idea by the late American miniaturist Bob Lincoln (1937-2017) who composed thousands of miniatures. This one is really special with battery mates and an unusual aspect: change of rear battery piece. 1.Re5? (-) 1...B~ 2.Re1 1...Bg3 2.hxg3 1...Bf2! Of course the best play is reserved for post key. Changed mates after a flight giving, sacrificial key. 1.Rg3! (-) 1...B~ 2.Rg1 1...Bxg3 2.hxg3 1...Kxg2 2.Rxg4 The problem won first prize in a tournament for miniatures with battery play. |

This might be one of the greatest two move miniatures of all time (IMO). It was an inspiration for my problem above. Notice the moves of the bR north, including the set check, have a response with a battery mate. 1...Re~ (Re2+) 2.B(x)e2 1...Rxd1 2.Qxd1 1.Qh8! (2.Re4/Re3/Re2/Rxe1) 1...Re4 2.Rxe4 1...Re3 2.Rxe3 1...Re2+ 2.Rxe2 1...Rxd1 2.Re1 1...Rf1 2.Rf5 1...Rg1 2.Rg5 1...Rh1 2.Rh5 1...Rxe5 2.Qxe5 Absolutely amazing! A perfect Karlstrom-Fleck with 4 threats and 4 total defenses separated by exactly that many moves. Two changed mates from the set play and a corner to corner wQ key. One may criticize the out-of-play wR which begs to form a battery, but that is it. |

One of the few miniatures in an FIDE album. A beautiful corner to corner key and some nice distant self-blocks. 1.Bh8! (-) 1...c6 2.Re5+ Kd6 3.Qe7 1...c5 2.Rb6+ Kd5 3.Qd3 1...Kd6 2.Qf7 (-) 2...Kc6 3.Qd5 2...c6 3.Be5 2...c5 3.Rb6 Nice variety in a beautiful open position. |

Now for something mathematical. The key makes three threats and the Black moves allow all possible combinations of the threats. Mathematically if we have three threats A,B, and C the possible combinations are {A}, {B}, {C}, {A,B}, {A,C}, {B,C}, {A,B,C}, \(\varnothing\). 1.Ke2! (2.Qe3/Qe5/Qg4) 1...Sg6 2.Qe3 1...Sg2 2.Qe5 1...Sf3 2.Qg4 1...f5 2.Qe3/Qe5 1...f6 2.Qe3/Qg4 1...Sf5 2.Qe5/Qg4 1...g4 2.Qe3/Qe5/Qg4 1...Kd4 2.Qd3 |

Here is something beautiful and possibly one of my best. The idea of R+B and B+R batteries is well worked in helpmates. But this seems to be a perfect form of the idea. One piece performs all moves in each solution. 1...Bb1 2.Rd7 Bg6 3.Be5 Bf7 1...Rh3 2.Be5 Rb3 3.Rd7 Rb6 A very high risk of anticipation and there are some front runners, but overall very elegant. |