lol, this has degraded into a discussion comparing the much superior Federer vs vastly inferior Sampras. I'll bite:
Under same circumstances (assuming exactly same surfaces), Nadal would lead Sampras 23 - 5 (and that's being very generous to Sampras).
Sampras is not getting any wins till July. He might be lucky to sneak a win in the slow Wimbledon conditions, that too if Nadal is off his game (most likely in 2006). Pete's best chance to get Nadal would've been the USO, but given that Federer & Nadal have never met there, tough luck Pete!!
Which brings us to YEC. Pete probably gets him in 2006 and 2007, but loses badly in 2010 and 2011 (in 2000, Sampras lost to Kuerten, who's quite inferior to Nadal, and in 2001, Pete was way past his prime --according to Pete clowns). So realistically, their h2h will look like 25-3.
I've said this before, and I'll say it again: Sampras is the luckiest 2-digit slam winner ever (men or women). His next generation (players who are roughly 5 yrs younger than him) comprised of Kafelnikov & Kuerten (LOL)!! And his "biggest" rival didn't show up for good portion of Pete's prime. Add of all it, what do you have? 14 slams. that's right. Under other eras (not including Federer, because if he played alongside Federer, he's not winning anything), he would've won 6-8 slams (tops). The rest were handed to him because of the lack of challengers in the generation that followed Pete.