Editing Pure mate (section)

===Steinkühler vs. Blackburne, 1863===
{{Chess diagram
 |tright
 |Steinkühler vs. Blackburne, 1863
 |rd|  |  |  |  |rd|  |kd
 |pd|pd|  |  |  |  |pd|pd
 |  |  |  |pd|  |  |  |
 |  |  |  |bl|  |  |  |
 |  |  |  |  |  |  |  |
 |  |ql|nl|  |  |  |pl|bd
 |pl|pl|  |  |  |nd|kl|pl
 |rl|  |  |  |  |  |rl|
 |The final position, a pure mate
}}

After providing their own definition, [[David Vincent Hooper|Hooper]] and [[Ken Whyld|Whyld]] cited a {{chessgloss|miniature}} won by [[Joseph Henry Blackburne]] against Alexander Steinkühler as an example of pure mate with Black as the mating side. Playing as Black and beginning with Black's 19th move, Blackburne initiated an attack on White's {{chessgloss|kingside}} consisting of three consecutive [[Check (chess)|checks]] (19...Qxf2+ 20.Kh1 Qg1+ 21.Rxg1 Nf2+ 22.Kg2) such that after each check, White had exactly one legal {{chessgloss|forced move|forced}} response, involving a [[queen sacrifice]]. Black then played his only available check (and mate) 22...Bh3{{chessAN|#}}, a pure mate in which Black's knight, light-squared bishop and king's rook {{chessgloss|coordinated}} with each other to give mate.

In the final position, the White king occupied a square away from the board's edge, such that its field consisted of the maximum eight squares. The three squares g1, h2 and g3 were blocked by friendly pieces (referred to by Hooper and Whyld as self-blocks{{sfn|Hooper & Whyld|p=364}}), none of which were also attacked by opposing units. h1 and h3 were attacked (or guarded) by the knight, and f3 and f2 were attacked (or guarded) by the king's rook. The square f1 is not attacked by the rook (the knight limits its line of attack); however, it is {{em|guarded}} by the bishop in that although the bishop may be said not to attack the square in the given position, the king is nevertheless prevented from fleeing along the bishop's line of attack, as it would remain in check. For this reason, some authors prefer to use the word "guarded" rather than "attacked" to describe such limitations on the king's movement.<ref name="Costeff" /> In any case, the king itself is attacked exactly once by the bishop, and is prevented from moving to any of the squares in its field for exactly one reason per square. Although it is a pure mate, the position is not an economical mate, as Black's queen's rook does not contribute to the checkmate. It is therefore also not a model mate, and thus also not an ideal mate.

{{block indent |1=[[Giuoco Piano]], (''[[Encyclopaedia of Chess Openings|ECO]]'' C54) <br /> 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4 Bb4+ 7.Bd2 Bxd2+ 8.Nfxd2 Nxd4 9.0-0 d6 10.Nb3 Nxb3 11.Qxb3 0-0 12.Re1 Nh5 13.e5 Qg5 14.exd6 Nf4 15.Bxf7+ Kh8 16.g3 cxd6 17.Nc3 Nh3+ 18.Kg2 Qf6 19.Bd5 Qxf2+ 20.Kh1 Qg1+ 21.Rxg1 Nf2+ 22.Kg2 Bh3# {{chessAN|0–1}}{{sfn|Hooper & Whyld|pp=326-327}}<ref>{{cite web |url=https://www.chessgames.com/perl/chessgame?gid=1028832 |title=Alexander Steinkuehler vs Joseph Henry Blackburne, Manchester (1863) |website=[[Chessgames.com]] }}</ref> }}