Prusa I3 mk3 - Not your average inconsistent first layer
If you repeat a test and the problem occurs in the same location, then you probably have a problem with your bed or build plate. However, picture 3 suggests to me that you may have a partially clogged nozzle. Manually extrude some filament. It should fall straight down. If it curls as it comes out of the nozzle, then you have a partial clog. Brass nozzles do wear out, so if you've put some hours on your printer, it might be a good idea to fit a new one.

Edit: I meant picture 3, not picture 4.