A piece is left attacked and undefended, or it was the only defender of something else and it moved.
Questions to ask before each move
Which of my pieces are attacked right now, and how many times?
What did the opponent's last move attack?
What does the piece I am about to move defend or block?
After my move, what can be captured for free?
Examples
18 featured positions, newest first. 1 from 25 October 2026; 1 from 24 October 2026; 6 from 23 October 2026; 1 from 22 October 2026; 3 from 21 October 2026; 1 from 20 October 2026; 2 from 19 October 2026; 3 from 18 October 2026.
Clock: this move took 1.0 s, and 24.9 s were left after it.
At move 41 Black was far ahead (+9.4). The pawn on g3 was attacked by the queen on f2 and the bishop on e5, and defended by the queen on b3 and the king on h3. 41...Qxg3+ started the exchanges, and after 42.Qxg3 Bxg3 43.Kxg3 Black had given a bishop for a pawn (−6.0).
The clock readings show 1.0 second for this move, with 24.9 seconds left against White's 10.1. 41...Kg8 keeps the winning position (+9.4). The game was later lost by resignation.
Count attackers and defenders before you capture. With equal numbers, the defender makes the last capture, even with little time left.
Clock: this move took 7.3 s, and 3:03 were left after it.
At move 11 the pawn on d5 was attacked twice, by the knights on f6 and e7, and defended twice, by the knight on c3 and the queen on d2. 11...Nfxd5 starts the exchanges and loses them: after 12.Nxd5 Nxd5 13.Qxd5 Black has given a knight for a pawn (−6.1).
With equal numbers of attackers and defenders, the defender makes the last capture. 11...h5, or another quiet move, keeps the game level (+0.7).
Count attackers and defenders before you capture. If the numbers are equal, the capture loses material.
Clock: this move took 17.5 s, and 2:20 were left after it.
The bishop on e2 was attacked by Black's queen on b2 and defended only by the queen on d1. 17.Qc1 left it with no defender, so 17...Qxe2 won a piece (−3.7). 17.Qe1 keeps the bishop protected (+1.0).
Clock: this move took 2.8 s, and 2:59 were left after it.
After 3...Bb4 the pawn on e4 was attacked by the knight on f6 and defended only by the knight on c3. 4.Bc4 allowed 4...Bxc3 5.dxc3 Nxe4, and a pawn is lost (the engine now rates White at −0.7). 4.e5 gains time and keeps a small edge (+0.9).
When a pawn has one defender, an exchange that removes the defender wins it. Check what defends your pawns.
Clock: this move took 1.8 s, and 2:59 were left after it.
Black's knight on h5 attacked White's undefended bishop on f4. 11.Be2 attacked the knight in return, but 11...Nxf4 captured first and also forked the queen on d3 and the bishop on e2 (−4.1). Moving the bishop away, 11.Bd2, keeps +2.3.
A counter-attack only works if it takes away the attacker first. Otherwise move or defend the piece.
Clock: this move took 13.4 s, and 2:36 were left after it.
The pawn on g5 was defended by Black's queen on f5. 14.Nxg5 won the pawn but lost the knight to 14...Qxg5 (−5.3). White was already slightly worse, and 14.Nxc5 was the move to find: it trades the knight for the bishop and keeps the game close (−1.1).
Before capturing, count who defends the target. A defended pawn costs a piece if the capturing piece is worth more.
Clock: this move took 9.9 s, and 1:52 were left after it.
White's queen on f3 was attacked by the rook on f8 and protected only by the pawn on g2. 25.e6 pushed a pawn instead of dealing with that, and 25...Rxf3 26.gxf3 cost a queen for a rook (−3.0). Moving the queen with 25.Qe2 keeps an advantage (+2.3).
A pawn push is not a defence. First answer every attack on your pieces.
Clock: this move took 4.1 s, and 1:47 were left after it.
At move 21 Black was clearly ahead (+6.8), but White's queen had just recaptured on d5 and now attacked the rook on a8, which had no defender. 21...Nc5 did not deal with it, and 22.Qxa8+ won the rook (−5.8).
Black resigned after 22.Qxa8+. 21...Re8 moves the rook and keeps the lead (+6.8). The knight move took 4.1 seconds, with 107.4 seconds left.
After every capture by the opponent, ask what the capturing piece attacks now.
Clock: this move took 5.2 s, and 35.9 s were left after it.
In this endgame the bishop on e6 was attacked by the knight on f4 and had no defender. 40.b5 ignored the threat and 40...Nxe6 won the piece (−6.8). Any bishop retreat, such as 40.Bc8, keeps the game level.
In every position, first list your pieces that are attacked. Do that before advancing a pawn.
Clock: this move took 7.1 s, and 1:40 were left after it.
After 22.Bf4 the bishop was attacked by the bishop on d6 and defended only by the queen on h4. Black adds a second attacker with 22...Qf5, and the line 23.Kb1 Qxf4 24.Qxf4 Bxf4 wins a piece.
22.Bd3 offers a bishop trade instead and keeps a lead of +4.7.
Count attackers and defenders of a square before moving a piece there.
Clock: this move took 1.6 s, and 1:12 were left after it.
On f5 the white knight blocked the diagonal from Black's queen on g6 to White's queen on d3, and the queen on d3 had no defender. When the knight moved, 25...Qxd3 won the queen (after a rook trade on e1 first).
25.Ne7+ was the safe way to use the knight: it forces a queen trade and wins the exchange, keeping +2.2.
Before moving a piece, ask what it is blocking. A piece between two queens is a shield.
Clock: this move took 1.0 s, and 5.4 s were left after it.
At move 44 Black had just made a new queen on a1 and was clearly winning (+7.4). 44...Qb1+ moved it to a square guarded by the bishop on e4, and nothing defended it there, so 45.Bxb1 took it (−6.9).
The clock readings show 1.0 second for this move and 5.4 seconds left, against 37.3 for White, and the game was lost on time right after 45.Bxb1. 44...Qd4 keeps the queen and the win (+7.4).
With seconds left, a safe move beats a check. Before giving check, ask whether the checking square is guarded.
Clock: this move took 41.5 s, and 1:28 were left after it.
At move 21 the black knight on f4 was defended by the queen on h4, the pawn on e5 and the rook on f8. 21.Qxf4 took it with the queen, and after 21...Qxf4+ Black had won the queen for a knight (−9.3).
The capture was not hurried: it took 41.5 seconds by the clock readings, with 88.8 seconds left. 21.Re3 keeps White ahead (+1.3).
Count defenders before capturing with the queen. If the target is defended even once, the queen is lost for it.
Clock: this move took 9.0 s, and 1:23 were left after it.
At move 20 Black was clearly ahead (+7.2). 20...Bxc3 took the pawn on c3, but the pawn on d2 defended it, and 21.dxc3 won the bishop. Black then won the c3 pawn as well, but two pawns for a bishop left the game about level (+0.3).
The capture took 9.0 seconds, with 83.1 seconds left. Three moves later 23...f5 lost the game, and Black resigned. 20...h5 keeps the lead (+7.2).
Before capturing a pawn, count its defenders. A pawn defended by another pawn is rarely free.
Clock: this move took 9.2 s, and 1:22 were left after it.
At move 25 White was clearly ahead (+4.6), but the knight that had just arrived on f5 attacked the rook on e7. 25.c3 left the rook there, and the engine gives 25...Nxe7 with −6.4. 25.Rd7 moves the rook to safety and keeps the advantage (+4.6).
Black answered 25...Rf8 and missed the capture. 26.g4 then left the rook on e7 again; the engine rates that position at −6.2, and this time 26...Nxe7 followed. After 27.Bxe7 Re8 the game ended by resignation. The two moves took 9.2 and 3.9 seconds, with 82.0 and 78.1 seconds left in this 3+0 game.
After every opponent move, ask what it attacks. A threat that was not carried out is still there on the next move.
Clock: this move took 13.3 s, and 2:36 were left after it.
At move 6 the white queen on d4 aimed at the pawn on g7, and the bishop on f8 was its only defender. 6...Be7 moved that defender away, and 7.Qxg7 followed (−8.5). From g7 the queen attacked the rook on h8 and, together with the bishop on c4, the pawn on f7.
The game ended at once with 7...Bf6 8.Qxf7#. 6...Be6 keeps the position playable (−0.8). The bishop move took 13.3 seconds, with 156.8 seconds left.
Before moving a piece, ask what it is guarding. A bishop on f8 often guards g7 against a queen on the long diagonal.
Clock: this move took 6.1 s, and 54.2 s were left after it.
At move 25 Black was clearly ahead (+4.9). 25...Be3 put the bishop where the pawn on f2 and the queen on b3 attacked it, and only the queen on d2 defended it. The engine's reply 26.Rad1 attacks that queen, and the bishop loses its defender when the queen moves (−5.3).
White played 26.Nh1 and missed it, so Black was ahead again, but the game was later lost on time. 25...Be3 took 6.1 seconds; Black had 54.2 seconds left against White's 105.9 in this 3+0 game. 25...Rc3 keeps the lead (+4.9).
Count attackers and defenders of the square before putting a piece there. A piece defended only by the queen falls when the queen is chased.