How a kiss happensThe crossing of two paths and timing

ScalesReference linePath

Reference position

Spinside +3 · high

1/2

Ball fraction1/2

Speed3/5

The cue ball hits the left side of ball 2 at half-ball (high hit, right running spin 3, speed 3) and goes to ball 3 via the left long, top short and right long cushions. Ball 2 goes up to the top short cushion and comes back. Because at half-ball the two balls leave at about the same speed, while the cue ball is going from the left long cushion to the top short cushion, ball 2 is coming back off the top cushion to the same point: they collide in the red area.

A kiss is when the cue ball, after hitting ball 2, collides with it again. Two conditions are needed together: the paths of the two balls must pass through the same point, and the two balls must arrive at that point at the same time. A crossing on its own is not a danger; timing decides the danger. Timing is mostly set by the ball fraction: around half-ball the two balls leave at about the same speed; on a full hit ball 2 is fast and the cue ball slow; on a thin hit it is the other way round.

When? As a short check before every shot; especially when ball 2 will travel on or near the cue ball's cushion path, when ball 2 is near a cushion, and when both balls are heading to the same area (the same corner, the same long cushion).

Tips

1When you hit around half ball (1/3–1/2 ball), the cue ball and ball 2 leave at about the same speed. If their paths cross, the two balls can arrive there at the same time; the kiss (the two balls colliding again) happens most often at this ball fraction.
2If you hit 3/4 ball or fuller, ball 2 leaves fast and the cue ball slow. Ball 2 reaches the crossing point first and is gone before the cue ball arrives.
3If you hit 1/4 ball or thinner, the cue ball keeps its speed and ball 2 moves slowly. The cue ball passes before the crossing, or ball 2 stops without ever reaching it.
4Do not stop after drawing the path of ball 2 up to the first cushion; also draw the part after it comes back off the cushion. Most kisses happen as ball 2 comes back off a cushion; for example, while ball 2 is coming back off the top short cushion, the cue ball is also heading to the top cushion.
5If ball 2 is very close to the cushion (less than half a diamond), do not hit it full. A ball 2 hit full comes straight back off the cushion and hits the cue ball, which has not yet moved away (a kiss-back). Hit it thin so that ball 2 strikes the cushion at a narrow angle and moves away.
6Do not try to prevent the kiss just by hitting harder: both balls speed up by the same ratio and still reach the crossing at the same time. Speed only helps if the lengths of the two paths are very different, or if you want ball 2 to stop before reaching the crossing (hit slowly).
7Name the crossing point after a diamond on the table (for example, 'in front of the 3rd diamond of the left long cushion'). Then count how many cushions each ball takes to get there; the ball with more cushions usually arrives later.

Voice coach

PRO

The voice coach is part of the Pro and Club plans.

See plans

Watch outThe paths in the diagrams are ideal: the cushion rebounds of ball 2 are drawn without spin (angle of incidence = angle of reflection), those of the cue ball as an angle opened or closed by spin. On a real table the cloth, the cushions, the speed and the curve of the shot shift the path slightly; think of the red area as one ball diameter wider.

Watch outIn the risky examples the paths drawn are the planned paths. If a kiss happens, the cue ball is deflected in the red area and does not reach ball 3; ball 2 does not stop where drawn either.