The B-String Shift

The B string (2nd string) is the rebel of the guitar. Because of the G-to-B major third tuning interval, scale shapes "kink" or shift one fret to the right when they cross onto this string.

Why Master It?

This shift confuses everyone. By specifically drilling the notes on the B string, you innoculate yourself against this confusion. You will stop hitting "wrong" notes in scale runs and start seeing the B string as a melodic bridge rather than a stumbling block.