We've all been burned by dud performances from fantasy quarterbacks in the past.

That's especially true if you try to stream the position, meaning you play waiver-wire talents in promising matchups until you find a quarterback who sticks and is worth an every-week nod.

That's why investing an early-round pick in the position comes across as a defensible strategy. Why play Ryan Fitzpatrick when you can play Aaron Rodgers?

But when it comes down to it, are these high-cost quarterbacks really worth it if you're seeking a combination of high floors and high ceilings?

Let's see how that panned out in 2015.

The Approach

We're going to examine player outputs from Weeks 1 through 16 (because Week 17 should be a non-factor in your fantasy leagues) and check out a few things.

We'll see how many fantasy points per game a player produced and the standard deviation for a player's weekly totals, which will indicate how up-and-down those point totals were throughout the year. After all, not all 18-point-per-game quarterbacks are made equally, but we can tend to view them the same way at year's end.

By subtracting or adding the standard deviation from the per-game averages, we can see where 68% of the player's outcomes fell, which is about 11 games out of a 16-game schedule. Sure, there's some math behind it, but I like to prefer that it's just magic.

Anyway, with some calculating, we can find out just how "consistent" or how much "upside" players provide on a realistic basis.

We're looking at games with at least 10 passing attempts or more to try to limit the impact of in-game injuries or backup players seeing a few snaps at the end of a game. We'll also examine players with at least eight games with 10 or more attempts. That way we're not reacting too much to small samples, which is always problematic when a season is just 16 games.

Who were the kings of consistency at the quarterback position in 2015?

The Results

I think a good place is to begin by looking at ceilings, meaning a player's points per game in qualified contests plus one standard deviation, derived from their weekly point totals. By doing that, we can see which players also offer a nice floor each week in addition to some upside.

Note the bolded values in the floor column ("68% L"), which indicate players with realistic floors of at least 12 points per week.

Last year, 9 of the 30 qualified quarterbacks posted realistic floors of at least 12 points in games with at least 10 attempts, and 16 offered at least 10 points per week on the low end.

This is the reason why anybody who takes a quarterback early and says, "He's going to put up 20 points per game" is wrong.

And the bigger issue, perhaps, is that other players have ceilings that are pretty close to those belonging to the elite: 25 of the 30 quarterbacks offered ceilings of at least 20 points, which means that nearly every quarterback has some upside.

But you have to pick and choose when to employ some of these boom-or-bust quarterbacks, such as Ben Roethlisberger or Marcus Mariota, who offered realistic ceilings of 28 points or more but floors of 10 or fewer points.

Still, Mariota's ceiling (28.6 points) was nearly identical to that of Russell Wilson's (28.7). If you employ these waiver-wire talents in the right matchups, you can combat even the most elite quarterbacks on your opponents' rosters (and that's not necessarily possible only with hindsight).

Draft Cost

If you thought about it while perusing the table above, you probably realized that some of the players with the biggest ceilings and floors weren't exactly early-round draft picks. That's pretty much the truth. If you're drafting a quarterback early for safety, you might be disappointed.

You might not, but look at the draft cost -- according to real, 12-team drafts on MyFantasyLeague after August 1st -- from last year for the nine quarterbacks with floors of at least 12 points.

Sure, Tom Brady, a 6th-rounder, was great last year, and so was Cam Newton, a 7th-rounder, but players such as Carson Palmer, a 13th-rounder, and Andy Dalton, a 14th-rounder, posted similar levels of weekly "safety."

In fact, six of the nine players had ADPs of the 13th round or later.

And, yes, Aaron Rodgers and Andrew Luck had to deal with injuries -- either personal or to their teammates -- so the early-round investments (Rodgers was taken at 2.01, and Luck was taken at 1.07) tanked. But that doesn't change the fact that some of these late-round fliers produced at similar levels to some of the other passers who were taken early in drafts.

After all, only six of the 30 passers posted at least 10 fantasy points in each of their qualified games: Wilson (4.01), Brady (6.11), Newton (7.12), Palmer (13.02), Jameis Winston (13.12), and Fitzpatrick (22.04).

What It Means for the Position

Honestly, there's little evidence in these numbers to suggest investing early-round draft capital on quarterbacks was a worthwhile investment last season, and the same was true in 2014. And that's before getting into how taking a quarterback early limits your chances at a playmaker at other positions.

Few fantasy passers were worth rolling out week after week regardless of opponent, and that means drafting one early is a hard move to justify.

Next, we'll break down how running backs fared by these same measures last season.