A gravity-pick Lotto machine

The Lotto Machines

There are two main types of Lotto machines: gravity pick and air mix. The machines have a few things in common:

  • They are designed and proven using statistical analysis to produce random combinations of numbers.
  • The balls are always visible during the mixing and drawing process -- they never disappear inside tubes or chambers. This helps prevent tampering; and since the drawings are televised live, it gives the viewer confidence that the drawing is not being fixed.

The gravity-pick machine is perceived to be more secure than the air-mix machine, perhaps because of a tampering incident that occurred in 1980 in Pennsylvania.

One common type of gravity-pick machine uses solid rubber balls. The balls are dropped into a chamber where two paddles, which spin in opposite directions, mix the balls. The operator actuates a sliding door at the bottom of the mixing chamber. One at a time, six balls pass through a clear tube into a clear display area where the numbers can be read. An optical sensor detects the passage of each ball, allowing only the correct number of balls to pass through the doorway.

An air-mix Lotto machine

The other type of machine that is commonly used for Lotto is the air-mix machine. This type of machine uses ping-pong balls that are painted with numbers and carefully calibrated for size and weight. These balls are released into the machine and jets of air blow up through the chamber to mix them.

To select a set of balls, the operator opens a valve that allows air out of the machine through a tube or a set of tubes near the top of the machine. Once the valve is open, balls are blown into the tube; they are then transferred through another clear tube into a display area for reading.

Since 1980, security procedures have improved. Here are some of the ways in which different states ensure the security of their lottery drawings:

  • The New York Lottery maintains several duplicate sets of Lotto balls. A set is chosen at random before each drawing.
  • The balls are weighed before and after each drawing to make sure no tampering has taken place.
  • The equipment is all kept in a locked vault until just before the drawing.
  • The Oregon State Lottery is overseen by the Oregon State Police. A detective attends each drawing to ensure the security.

In 1980, there was a scheme to fix the Pennsylvania Lottery's Daily Numbers game. In this game, three single-digit numbers are drawn. The conspirators injected all of the numbers except for the fours and sixes with white paint so that they were too heavy to be blown up to the top of the chamber.

When the numbers were selected on live television, sure enough, the winning number was 6 - 6 - 6. Before the numbers were drawn, the conspirators had purchased many tickets all over the state for the eight different combinations that are possible with sixes and fours. They ended up winning $1.8 million. Click here for a detailed account of the whole story.

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