Seam bowling in cricket is often used interchangeably with pace bowling. Pace bowlers are those players in the eleven who take wickets through their pace and imparting variations on the ball after the ball bounces on the 22 yards pitch.
The movement that the ball makes when it is released by a pace bowler depends on three things. Firstly, how windy are the conditions? A breezy environment is likely to be a huge catalyst in swinging the ball, with the bowler only having to read the breeze nicely. Secondly, the nature of the pitch. A grassy surface will increase the pace with which the batter receives the ball. Finally, the position of the bowler’s fingers on the ball, also known as the seam position. The three common variations to the conventional seam position are the cross seam, wobble seam, and scrambled seam. This explainer describes the wobble seam.
The conventional seam position is one where the bowlers rests his or her index and middle fingers on the seam (stitched elevations running at the centre of the cork ball). This early position, along with a technically sound release of the ball as guided by the wrist decides the amount of swing on the new ball. As the ball gets older, the rough surface of the ball negates the amount of swing and batters are better able to predict the trajectory of the ball.
Bowlers opt for a wobble seam when the ball has stopped swining. The wobble seam position is one where instead of the seam being underneath the bowler’s fingers, it is positioned slightly acute of the bowler’s fingers. Notably, the seam is neither completely or nearly placed horizontally. Simply put, the wobble seam is an imperfect execution of the conventional seam.
What makes the wobble seam unique is that neither the batter, nor the bowler can predict the trajectory of the ball. When mid-air, the seam wobbles (hence the name) while being upright and creates a wayward deflection after pitching. The seam makes contact with the pitch diagonally, making the ball travel differently. Since the post-bounce parabola of the ball cannot be determined, the line slightly outside the off is the safest one to direct the ball at to minimize the risk of giving runs in the form of extras (e.g. wide).
The wobble seam is thus a unique variation which the bowlers opt for when they run out of options for swinging the ball.
