I don't think I've taken back-to-back RBs in a draft since about 2005. In fact if trends continue like they have in the NFL, there's less and less evidence to believe that that is solid strategy. I'm all for picking an RB in round 1, especially if you in the top 7 or 8 but the NFL is more and more becoming a passing heavy league. Introduce RB tandems and more athletic QBs as the enmerging norm and there is about zero reason to pick a RB in rounds 1 & 2. 8+ years ago you had guys like Tomlinson competing for TD records. Now days the vast majority of RBs score fewer touchdowns than many WRs or even some TEs.
I get what you're saying, and you're right- every year the league becomes more and more pass-happy. But I feel like this makes RB's even more valuable in the early rounds just from a supply and demand point of view. There are so few every down workhorse backs nowadays that if you can start two every week, you've got an edge over teams that maybe have one good RB and a black hole at the RB2 spot. Also, as the passing numbers continue to climb, there are more and more quality QB's and WR's available. True, there are only so many top tier studs to go around, but the gap between a guy like Brees (who you'd need to use a 1st or early 2nd round pick to get) and guys like Stafford, Ryan, or Luck (who you may be able to get as late as round 4 or even 5) is shrinking. Meanwhile, once you get past the 10th-15th RB's, production at the position falls off a cliff.
If the best player left is a RB and there's no viable Top 5 QB or Top 5 WR/TE left then ok. But margin for error is very thin and you will get left in the dust in basically every other single scoring category if you over-reach to get 2 RBs and are saddled with say Percy Harvin & Pierre Garcon as your WR1 & WR2, then good luck to you.
I don't mean to imply that I think it's written in stone that I have to go RB-RB with my first two picks. Obviously it depends on what's left when it comes around to my pick again. If the best thing left at RB is the 14th guy on my list, but my #3 WR is still there, then that's a no-brainer. Last year, picking last (12th), I went RB-RB with my first two picks, then with my 3rd and 4th picks (36th and 37th overall) I grabbed Andre Johnson and Hakeem Nicks. I was much happier with those WR's than I would have been with any of the RB's left at that point. I think that's my main thing with taking RB's early; I just dread how pathetic the options become later.
All good draft strategy should take into account how the league is scored. For example in PPR leagues, if you are sitting around to say late round 4 or round 5 to make your first WR or TE pick the it will pretty difficult to win that league.
Absolutely. My league does a half-point per reception, so a guy like Ray Rice gets a bit of a bump, but not quite as much as in a full PPR league. It's definitely important to keep that stuff in mind. Plus, you can draft a great team using almost any strategy for your early picks if you're able to hit on some good value picks later on. Two years ago when Arian Foster had his big breakout year, he pretty much single-handedly led me to my leagues Super Bowl. I drafted him as my 3rd RB in the 7th round (81st overall) and got lucky. Last year I was targeting Eli Manning in the 5th round, but the guy picking one spot ahead of me took him.... so I had to settle for Peyton. Sometimes it's better to be lucky than good.