Is the pressure getting to Sebastian Vettel?

MARINA BAY, Singapore -- In a championship battle that could easily be decided by small mistakes, Sebastian Vettel made another on Friday night in Singapore. As he rounded the penultimate corner towards the end of a quick lap, he clipped the barrier on the exit with his right rear wheel. The car returned to the pits leaking hydraulic fluid, and with it his session was over.

In the grand scheme of things it was pretty small error -- the sort that comes with the territory during a practice session on a street circuit -- but given his season so far, it was another unnecessary concession to his title rival Lewis Hamilton. The early exit from Friday night's practice session meant he was unable to…