I understand that you feel that way, but we're naturally biased towards overconfidence in our own beliefs. For instance, you talk about only doing it for guy's you're "99% certain about", but I guarantee you that your success rate on guys you're "99% certain about" is a lot less than 99%. Hell, Reggie Bush was once one of your 99% guys, and you haven't made 99 more correct calls since then to offset that miss. Stewart's another example. I know, unprecedented situation, unanticipated circumstances, no way you could have predicted it. I agree, I'm just pointing out there are a lot of ways for a pick to go wrong even if you nail the talent evaluation. I can't even list all of them, because some of them are undoubtedly "unanticipated" or "unprecedented".
The reality is even "sure things" like Richardson are maybe 75% plays at best. Even if you're extremely confident in him, his EV will never be double Peterson's. his upside is, sure, but not his EV. I think his upside makes him worth the risk, and I'd trade Peterson for him in a heartbeat, but I also temper my rankings enough that I don't think the gap is all that colossal. Richardson is a top 5 pick, but I've still got Peterson in the top 15.
By and large, I've almost never regretted it when I made a big preemptive move to get a top young talent before his value really blew up. I've actually made a lot of my best picks that way over the years. These are my five most recent startup drafts:2008 - Calvin Johnson with the 19th pick.
http://football4.myfantasyleague.com/2008/options?L=60795&O=17
2009 - Hakeem Nicks at 5.06 and Percy Harvin at 6.01.
http://football22.myfantasyleague.com/2009/options?L=13679&O=17&DISPLAY=CONFERENCE01
2009 - Trent Richardson with the 73rd pick. Andrew Luck with the 152nd pick.
http://football15.myfantasyleague.com/2009/options?L=42903&O=17
2010 - Demaryius Thomas with the 39th pick.
http://football4.myfantasyleague.com/2010/options?L=74815&O=17
2012 - Doug Martin with the 64th pick.
http://football27.myfantasyleague.com/2011/options?L=74696&O=17
There are some duds in there too and some mediocre picks, but there would be busts even if I had only been drafting established veterans. Some times those guys inexplicably fall off a cliff too (as any Fitzgerald owner could tell you). The fact that Reggie Bush and Jonathan Stewart are used as the worst case scenario examples actually indicates why this strategy can be so solid. I took Bush at 1.03 in one league before he was drafted and while some of the other players taken in that round have clearly outshined him since then, he has given me quite a few good ppg seasons over the years and is still on my roster after all this time. And that's a guy who has definitely not lived up to his billing. I took Stewart high in a couple league and he's been a disappointment, but there's still plenty of time for him to repay my faith and he's sustained pretty decent trade value throughout his whole career even if the production hasn't warranted it.
I am not saying that I always get it right, but in general when I have an extremely high level of confidence in a draft prospect or young player, it's pretty rare that he becomes a major disappointment.
One of the only reliable ways to acquire top talent at reasonable prices in dynasty leagues is to pounce before the player reveals the extent of his talent to the entire FF community. The fact that some owners need to wait and see before they make a big investment in a prospect is really exploitable
IF you are able to consistently make good calls about which prospects are legit. I have some leaks as an FF player, but overconfidence in draft prospects or unproven young players is actually not something that has been a big problem in my drafts in recent years. In fact, getting in early on guys like Martin, Thomas, and Harvin is almost the sole reason why some of my teams have been competitive.