The Mortimer Trap is a
chess openingtrap in the
Ruy Lopez named after
James Mortimer. The Mortimer Trap is a true trap in the sense that Black deliberately plays an inferior move to tempt White into making a mistake.
The trap begins with Black playing the
Berlin Defense to the Ruy Lopez. Although the Berlin was much more popular in the 19th century than in the 20th, it "became the height of
theory when
Vladimir Kramnik used it as his main defense to defeat
Garry Kasparov in their 2000
World Championship match."[1]
4. d3
White plays a quiet alternative to the more common 4.0-0, 4.d4, or 4.Nc3 (the last would transpose to the
Four Knights Game).
I. A. Horowitz and
Fred Reinfeld wrote that 4.d3 is "
Steinitz's move, with which he scored many spectacular successes during his long reign as
World Champion."[2]
The Mortimer Defense,[4] intending to reroute the
knight to g6. This rare move loses
time and thus is inferior to other moves, but it sets a trap. White has several acceptable replies, for example 5.Bc4 c6 6.Nc3 Ng6 7.h4
! with the upper hand and an attack (
Keres,
Olafsson),[3] but the tempting capture of the black
pawn on e5 is a mistake.
Attacking the white
bishop and threatening 6...Qa5+. If the bishop moves (6.Ba4 or 6.Bc4), Black wins a piece with 6...Qa5+,
forking the white
king and
knight.
Covering a5 and thus preventing 6...Qa5+, and threatening
smothered mate with 7.Nd6#.
6... Ng6!
After 6...d6 7.Ba4, Black forks the white bishop and knight with 7...b5, winning a piece for two pawns.[5] Likewise after 6...Ng6, Black will win
material.
Discussion
Mortimer played his defense at the
1883 London tournament against
Berthold Englisch,
Samuel Rosenthal, and
Josef Noa, losing all three games.[6]Johannes Zukertort, the tournament winner, also played it against Englisch, the game resulting in a
draw.[7] Zukertort wrote of 4...Ne7, "Mr. Mortimer claims to be the inventor of this move. I adopted it on account of its novelty."[8] The first edition of the
treatiseChess Openings, Ancient and Modern analyzed 5.Nc3 Ng6 6.0-0 c6 7.Ba4 d6 8.Bb3 and now the authors gave either 8...Be6 or 8...Be7 as giving Black an equal game.[9] A bit more recently, Horowitz and Reinfeld observed of 4...Ne7, "This time-wasting retreat of the Knight to an inferior square blocks the development of the King Bishop ... . Yet it is a matter of record that this
pitfall had a vogue for many years."[2]