Every coach already owns the alternative: a brand-new leather ball. It swings beautifully, and it keeps swinging for about twenty minutes. Here is how the two compare over a season.
| New leather ball | SWINGA | |
|---|---|---|
| Swings out of the wrapper | ✓ | ✓ |
| Still swinging after one session | ✗ | ✓ |
| Swings more as it gets older | ✗ | ✓ |
| No shining required | ✗ | ✓ |
| Keeps its shape | ✗ | ✓ |
| Works in the wet | ✗ | ✓ |
| Safe on a $1,000 bat | ✗ | ✓ |
| Goes through a bowling machine | ✗ | ✓ |
| True leather feel off the bat | ✓ | Closest with 156 g |
| Legal for match play | ✓ | ✗ |
| Cost | $20 to $110 | $19.95 |
Why leather stops swinging
A leather ball swings because one side is polished and the other is rough. The air behaves differently across the two surfaces and the ball moves towards the side with more drag. The lacquer on a new ball gives you that difference for free, and net sessions take it away within an hour. Once both sides are the same, there is nothing left to make the ball deviate, and that is the ball your players spend the rest of the session facing.
Why the SWINGA goes the other way
The SWINGA builds the difference into the ball itself. One half is dimpled, one half is smooth, and no amount of use rubs that away.
Brand new, it swings towards the dimple side. As it wears in it starts to reverse, moving towards the shiny side instead, and it swings more the older it gets. A leather ball is at its best the moment you unwrap it. A SWINGA is at its best a season in.
If you want the physics rather than our word for it, we asked a fluid dynamicist at the Australian National University to explain it. His answer is on the How to SWINGA page.
What it will not do
It is not a match ball and we do not pretend otherwise. You cannot play a graded game with it, and a 156 g SWINGA still is not a leather ball off the middle, though it is the closest of the two weights.
What it does is give every player at training a ball that swings, for the whole session, every session, for seasons.
The maths for a club
A dozen new leather balls to run one swing session costs somewhere between $240 and $1,320, and they stop swinging before the session ends. A 12 pack of SWINGAs is $198, works out at $16.50 a ball, and they are still swinging next season.
Have a look: single ball · 6 pack · 12 pack · Clubs & Schools