Every time late April rolls around, Fantasy Football fanatics start frothing at the mouth over the incoming crop of rookies. Without having played a second of NFL football, the die-hard football fans start pouring over data and scouting reports on hundreds of players.

This year everyone's eyes are on guys like C.J. Spiller, Ryan Mathews and Dez Bryant. Many have already declared their love for these guys even though they haven't learned their own playbooks. In time they'll know their role and start developing to the specifications of what their teams want them to be. But as that's happening, expectations for Fantasy Football production start to ramp up.

Stop the madness!

In an effort to show just how unimpactful rookies have been over the past four years, we've put together this interactive chart showing you how rookies have finished compared to their veteran counterparts, cross-referencing the information with the average draft position of everyone involved. Please note that for the sake of condensing the data as much as possible, we eliminated the strong majority of veterans who didn't score more than 50 Fantasy points in a season since they were plentiful and considered useless. We considered most rookies regardless of their Fantasy point total.

Also note that undrafted players line the bottom of the chart – we felt it was necessary to include rookies and veterans who weren't drafted in Fantasy leagues but still found a way to make an impact.

We recommend you sort this data by position and by season to get a legitimate feel for how rookies have fared at each position over the last four seasons. Or, if you don't feel like sorting the chart, you can review our thoughts below.

•The first thing that stands out: Over the last four years only 13 running backs and receivers have posted 125 or more cumulative Fantasy points. That mark of 125 points is a barometer for determining a starting rusher or receiver in the most basic of Fantasy leagues. Most running backs and receivers in the NFL don't put up 125 points, but the ones who are considered reliable Fantasy options surpass that total.

That barometer for quarterbacks is around 225 Fantasy points. No Fantasy rookie quarterback over the last four years has topped that total in standard-scoring leagues, though Vince Young (2006) and Matt Ryan (2008) have come very close.

For tight ends the magic number is about 80 Fantasy points, and even that is a bit of a stretch since most leagues have about 20 tight ends total on rosters. Just one tight end: John Carlson (2008) topped 80 Fantasy points as a rookie.

You're better off passing on rookie quarterbacks and tight ends in drafts.

When you compare all of that data vs. the fact that 26 rookies were taken within the first 120 picks on average over the last four years, a bell should be going off in your head: Don't go hog wild on rookies. Consider Raiders running back Darren McFadden the poster boy for this: His average draft position in 2008 was around 36th overall, and he totaled 85 Fantasy points. A toe injury played a big role in that number being what it was, but he still ultimately failed his Fantasy owners (and did again as a sophomore).

•Of all the positions, this chart makes it clear that running backs are the most valuable rookies to consider on Draft Day. That was accepted knowledge anyway. But for those of us who play Fantasy Football for the risk-reward factor, our study says you have a better chance of hitting it big with a prominent rookie than one you'll draft late or claim off waivers. Another statement that makes sense, but it makes sense in a major way: The 17 running backs picked higher than 120th overall averaged 121.2 Fantasy points while the 25 running backs picked after 120th overall averaged an unspectacular 70.48 Fantasy points.

But drill a little bit deeper and you'll find the wheelhouse for Fantasy rookie running back value: Of the six rookie rushers who were picked on average above 80th overall, their average Fantasy production was a whopping 152.8 Fantasy points -- and that includes McFadden's injury-prone rookie season.

But there is just as good of a value following those running backs: Of the 10 rushers who were picked on average between 80th and 120th overall, their average Fantasy production was 101.9 points. That's certainly acceptable value, especially if you can get closer to that 120th overall pick than the 80th overall pick.

Rookie running backs picked after 120th overall have not fared well (see the chart). Only two have broken into 200 Fantasy point territory while another four topped 100 Fantasy points.

So if you're set on taking a rookie running back, better make it a good one; of the 16 backs picked earlier than 120th overall, 12 were first-round picks, three were second-round picks and two were third-round picks. This certainly bodes well for Spiller, Ryan Mathews and Jahvid Best.

•Rookie wide receivers have never been terribly popular Fantasy options. Calvin Johnson is the only rookie wideout who was picked above 100th overall on average, and he was a good but not great choice as a rookie in 2007 (Dwayne Bowe did better and was taken roughly 100 picks later). Every other rookie receiver in our study wasn't picked until the middle-to-late rounds, which makes sense since it's rare for a rookie receiver to make an impact.

When one rookie receiver did make a huge impact, he was barely drafted at all. Only a handful of shrewd Marques Colston owners gobbled him up in 2006 drafts, and they did it with the 201st overall pick. Now if that doesn't tell you picking rookie receivers is a guessing game, I'm not sure what will.

We did catch one trend: Rookie receivers have been making positive steps to becoming more productive in Fantasy. If you click on WR in the chart, then view each year starting in 2006, you can see the green dots advancing past the 100 Fantasy point mark. Last season four rookie wideouts topped the century mark. Why is this happening? Teams changing their offensive philosophies and becoming more pass-oriented is forcing rookies into action sooner. That, and college teams are doing better jobs of preparing their players for the pros as far as playbooks and physical preparations are concerned.

Do you have a question or a comment for our Fantasy staff? Drop us a line at dmfantasyfootball@cbs.com. Be sure to put Rookies in the subject field. You can also follow Dave via Twitter at @daverichard.