Seesaw (Windmill) — chess tactic

Seesaw

Definition

In chess, a “seesaw” (also known as a “windmill”) is a forcing tactical motif where one side repeatedly alternates checks—typically with a rook and a bishop—so that the opponent’s king is driven back and forth between two squares. Each oscillation is accompanied by either a check with the rook or a discovered check from the bishop, allowing the attacker to “harvest” material in between checks or to force a decisive attack. The term evokes the back-and-forth motion of a playground seesaw.

How it’s used in chess

The seesaw appears most often in the middlegame when an enemy king is boxed in with limited flight squares, and a rook is placed next to that king, supported by a bishop on the long diagonal. The attacking side alternates moves so that:

A rook check forces the king to a fixed square.
On the next move, shifting the rook off the diagonal unveils a discovered check from the bishop.
Repeat: the rook returns with check, then vacates again—each time grabbing material or tightening the net.

Because every move in a seesaw is check (or discovered check), the defender has no time to counterattack. This is one of the purest examples of a forcing sequence in practical play.

Strategic significance

Strategically, the seesaw is significant because it converts time (a series of forcing checks) directly into material or mate. It often arises from a prepared attack, a successful decoy, or a prior sacrifice that exposes the enemy king. Understanding the seesaw helps players:

Recognize when a rook-and-bishop “battery” can be formed on a sensitive diagonal.
Evaluate when a speculative rook infiltration is sound due to the opponent’s cramped king.
Prioritize king safety and luft to avoid being tied to a fixed back-and-forth defensive dance.

Typical pattern and prerequisites

Common features of a classic rook–bishop seesaw include:

The enemy king is cornered (often on h8/h1 or a8/a1) with minimal escape squares.
A rook sits adjacent to the king (e.g., on g7 vs. a king on h8) and is protected by a bishop on a long diagonal (e.g., Bb2 controlling h8).
When the rook leaves the key square, a discovered check from the bishop occurs; when the rook returns, a direct rook check occurs.
Defenders lack sufficient pieces to interpose, and their king is “fenced in” by its own army or pawn structure.

Typical tactical companions include Decoy, Deflection, Discovered check, and overworked defenders (see LPDO / “Loose Pieces Drop Off”).

Examples and visualization

Textbook seesaw sequences often look like this conceptually (not a full game score): the rook checks the king on the 7th rank; next, the rook moves off that square to reveal a bishop check along the long diagonal; then the rook comes back with check—repeating while gobbling loose material. Each move is forcing; the defender is pushed back and forth with no useful in-between moves.

A famous illustration of the windmill/see‑saw idea is commonly associated with Carlos Torre vs. Emanuel Lasker (Moscow, 1925), a game that popularized rook–bishop oscillation as a tactical weapon. While many versions in training books present an idealized pattern, the core educational takeaway is the same: once the oscillation starts and every move is check, the defender is helpless to avoid massive losses or mate.

Recognize these visual cues on the board:

Rook planted next to the enemy king on the 7th or 2nd rank.
Bishop controlling the king’s corner via the long diagonal (e.g., b2–h8 or g2–a8).
No safe interpositions; every block either loses material or walks into a new check.

Practical tips

For the attacker:
- Check if the rook is fully supported—most often by a bishop—to start an unstoppable oscillation.
- Count the “free captures” you can make during the seesaw; don’t rush a premature mate if you can win overwhelming material safely.
- Watch for perpetual alternatives; if mate or material gain isn’t guaranteed, a perpetual check can still salvage a half‑point.
For the defender:
- Create luft (e.g., ...h6 or ...g6) before it’s too late; deny the attacker a fixed shuttle route.
- Interpose with tempo if possible, or return material to break the pattern.
- Trade off the attacking rook or the supporting bishop to stop the oscillation at its source.

Historical notes and anecdotes

The motif is widely known by its synonym Windmill, a term that grew popular in English‑language chess literature. In Spanish and several other languages, the image of a “mill” grinding material captures the essence of the tactic: once the mechanism starts, pieces get “ground down” as the rook and bishop keep swinging. Modern engines highlight that the seesaw is not just romantic-era showmanship; it remains a precise, concrete resource whenever king safety is compromised and interpositions fail.

Related terms

Windmill (synonym; the most common label for this motif)
Discovered attack and Discovered check (core mechanic)
Battery and Rook on the seventh / Pigs on the 7th (structural/positional precursors)
Decoy and Deflection (often used to initiate the tactic)
Back rank mate motifs (frequent finishing themes)

Interesting facts

Because every move is check, the seesaw denies the defender any practical counterplay—perfect “move priority” for the attacker.
Composers in chess problems frequently craft elegant seesaw sequences as thematic showcases—sometimes layering them with interference or line‑clearance ideas.
Even when it doesn’t win material outright, a seesaw can be used as a “forcing lever” to shuttle the king into a mating net or to drive it toward a corner for a decisive finish.