In a Key Number Wheel, one "key" number appears in every combination of the wheel. There are Key Number Wheels which have the same win guarantees as Abbreviated Wheels, but they contain fewer combinations. For a Key Number Wheel to be a guaranteed winner on the UK National Lottery, two conditions must be met:

All of the winning lottery numbers must be somewhere in the wheeled numbers, just like in regular wheels. The "key number" which appears in every combination MUST be one of the winning lottery numbers drawn. Key wheels have fewer sets to bet for a given guarantee, but if you don't hit the key you don't get the guaranteed win. Let's do a comparison between a Abbreviated Wheel and a Key Number Wheel:

If you wheel 12 numbers in an Abbreviated Wheel, a four-of-four win would require 132 combinations. In the Key Wheel, though, only 113 combinations would be required. Remember, though, that your "key number" must be among the winning lottery numbers. You should only use the Key Number Wheel when you feel strongly that your "key number" is going to be drawn.

The following is an example of a Key Number Wheel, which wheels eight numbers for a four-of-four win in five combinations. You'll note that the process is the same as for the Full and Abbreviated Wheel except you must write your "key number" under the "KEY" heading.

The Wheel = A B C D E F

1. KEY A B C D F
2. KEY A B C E G
3. KEY A D E F G
4. KEY B C D E G
5. KEY B C E F G