Reading Width
The reading width of a tactical analysis can be defined as the number of variations one explores while trying to reach conclusion about a certain position. The number of moves one "sees" at any step of the analysis is largely influenced by knowledge and intuition.
The other important factor in tactical analysis is reading depth.
Example
Someone who doesn't know this position by heart, but has some basic knowledge about vital points, will normally investigate only a and b.
Likewise here.
So, for a player with basic knowledge of vital points, the width of this position is about 4.
For a complete beginner, not having any knowledge of vital points, any of the six points is a viable starting point. This gives a width of about 6!=720 variations, before capture is reached. This position hence is out of reach for a complete beginner, unless gifted with exceptional reading abilities.
It is said that what distinguishes the professionals from the amateur, is that they are far more capable in keeping the width of their analysis under control, rather than being much better at reading very deeply.