X-ray attack Puzzles: Challenging Level

By the numbers

x-ray attack puzzles at challenging level: the numbers

There are 4,490 x-ray attack puzzles at challenging level, solved 15,227,848 times in total. The median rating is 1762.

Often combined with

Middlegame tactics · 2,609Endgame tactics · 1,824Checkmate · 1,513Sacrifice · 1,008Mate in 2 · 830Kingside attack · 609Mate in 3 · 538Back-rank mate · 476

Which openings produce them?

Sicilian Defence · 52French Defence · 26Scandinavian Defense · 25Queen's Pawn Game · 23Italian Game · 18Queen's Gambit Declined · 16Caro–Kann Defence · 15Indian Defence · 14

Counts computed from the full puzzle set.

How the solutions work · counted by a rules engine

What a typical x-ray attack solution looks like

Sample: 2,000 x-ray attack puzzles at challenging level (44.5% of all 4,490).

41.2% need 2 solver moves, 47% need 3 solver moves, 10.6% need 4 solver moves, 1.2% need 5 or more solver moves. Median rating: 1723 for the shortest solutions, 1857 for the longest.

55.9% open with a queen move. The first move captures in 50.6% and gives check in 69.2%; 34% end in checkmate, 70.4% involve a sacrifice, 52.6% have White to move.

How many moves does the solver need?

Which piece plays the key move?

What does the solver win?

Material balance along the whole line, counting every capture by both sides (pawn 1, minor piece 3, rook 5, queen 9):

How much is left on the board?

How it is counted: every puzzle in the sample is replayed move by move with a chess rules engine. A sacrifice means a piece that is captured on the very next ply and was worth more than what it captured itself (pawn 1, minor piece 3, rook 5, queen 9). Sample of 2,000 puzzles. Percentages are shares of the sample.

Where it happens

Where the key move lands

Where the solver’s first move ends, drawn from their own side (rank 1 is their back rank). Busiest squares: e8 (10.1%), d8 (7.8%), c8 (6.4%), f8 (5.3%), f7 (4.5%).

Counted from the same 2,000-puzzle sample. Squares under 1% are left blank.