Centering bed for calibration

These are the results on my LulzBot TAZ 6. I entered the commands on the Terminal Tab:

Send: G28 X Y ; Determine origins based on the endstops
[...]
Recv: X:-19.00 Y:258.00 Z:10.00 E:0.00 Count X:-1910 Y:25929 Z:16000
Recv: ok P15 B4
Send: G0 X0 Y0 ; Goto 0,0
Recv: ok P14 B4
[...]
Send: M114 ; Where are we?
Recv: X:0.00 Y:0.00 Z:10.00 E:0.00 Count X:0 Y:0 Z:16000
Recv: ok P15 B4
[...]
Send: M206 X-50 Y-50 ; Change the offset. Nozzle doesn't move.
Recv: X:-50.00 Y:-50.00 Z:10.00 E:0.00 Count X:0 Y:0 Z:16000
Recv: ok P15 B4
[...]
Send: G0 X0 Y0 ; Nozzle now moves to the "new" 0,0
Recv: ok P14 B4
[...]
Send: M114
Recv: X:0.00 Y:0.00 Z:10.00 E:0.00 Count X:5025 Y:5025 Z:16000
Recv: ok P15 B4

I originally tried M206 X50 Y50 but the subsequent G0 X0 Y0 Hit the endstop and failed. BTW, the [...] are suppressed temperature reports.