Hi,

If your talking the very standard seat clamp then
the position of the nuts fore or aft affects the
range of fore or aft of the seat position a lot.

The standard position is bolts to the rear and the
middle of the rails, bolts to the front is much
further forward, could work for some I guess.

I always use the standard seat clamp upsidedown
with the bolts always to the rear, as ever, YMMV.
(It looks the best by far.)

rgds,sreten.