[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "White to play and win"]
[Black "?"]
[Result "*"]
[Annotator "peter"]
[SetUp "1"]
[FEN "4K2k/6p1/6P1/3p4/8/8/2B2P1p/5Rn1 w - - 0 1"]
[PlyCount "7"]
[SourceVersionDate "2020.04.01"]
{[#]} {Peter Boll study} 1. Be4 $1 {clearing the d-file whilst at the same
time blocking the path for the future queen} (1. Ra1 $2 h1=Q 2. Ra8 d4 3. Rb8
Qh2 4. Rc8 Qh3 {etc}) (1. Rb1 $2 h1=Q 2. Rb8 Qh2 3. Rc8 (3. Ra8 $2 Qc7) 3...
Qh3 $11) (1. Re1 $2 h1=Q 2. Re7 $11 (2. Kd7 $2 Qh3+ 3. Kd8 Qh4+ 4. Kd7 Qg4+ 5.
Kd8 Ne2)) 1... dxe4 2. Rd1 (2. Rc1 $2 h1=Q 3. Rc8 Qh3) (2. Ra1 $2 h1=Q 3. Ra8
e3) (2. Rb1 h1=Q 3. Rb8 Qh2) 2... h1=Q 3. Rd8 Qh4 4. Ra8 {and it is discovered
checkmate in 2 as the queen cannot attack the rook nor pen in the white king} *