Going on a little J-class trip to US westcoast soon. Already have my upper deck seat pre-assigned. Just in case the plane is full and they need to op-up (looks good on Sabre so far)

I was wondering if my chances increase if I OLCI (because then they know that I will actually fly and not end up as a no show) - Or do they tend to decrease (since then my seat will be confirmed and I am taken care of and they'll rather see if there are no-shows and only op-up the last ones to check in if they absolutely have to)?
What are peoples experiences on this?
BTW can't MFU since I am booked through a travel agent (D-class).
[This message has been edited by GreatDane (edited Jan 29, 2004).]