This Pattern is for investigating your printbed.
It shows:

1. It can help you to find spots of bad adhesion (in the image above on the right)
   If your printbed has spots of bad adhesion you will see the difference while printing.

2. It shows the leveling of your printbed
   After printing you will see, if the leveling is consistent.

3. It reveals the bending of your linear rails (compare the right side with the bottom left corner in the image above)
   Some inconsistencies witch appears as problems with the leveling can be recognized as bending of the linear rods.

If the hight of the pattern is reduced in the center, this dose not necessarily mean your print bed is bowed upwards. In most cases it will indicate sagging of the linear rods. Especially if heavy components as steppers or aluminum base plates are sitting on the axis.

On an printer with moving y axis you will find some kind of valley in x direction with an nice even plain in the middle and noticeable ridge near the front an rear edges. This is caused by bending linear rods of the y axis, witch tilts the y carriage while traveling. If the carriages reaches the extreme position the inner edges are facing slightly downwards. This reduces the problem slightly.

Especially if the transition between the lowland in the center and the ridge at the edges occurs above the linear bearings, you will face this phenomena.

Demonstration on Youtube (sorry German)

This shows that mash bed leveling mostly copes with the bending of the rail ... alternatively it is worth to think about reducing wait and putting the bearings more apart. See 2-3-4-5-Owl