“Lottery ticket” is one of the most often used phrases among fantasy football experts and analysts, as they look to describe a player who could break out above and beyond their projections and find a high degree of success for a low price.

Like a lottery ticket, almost any of these players can result in a disappointing lack of return on initial investment. Taking a fourth wide receiver who has been impressive in the preseason with your third-to-last pick of a fantasy draft, only to see him targeted 20 times all season, would constitute as the typical lottery analogy that most Powerball players know and love: A very low barrier to entry with an even lower chance of winning anything.

But what makes many fantasy lottery tickets different than real lottery tickets is that not every player you gamble on in a fantasy league has the same low cost. Selecting Zach Sudfeld this season represents buying a one-dollar lotto ticket from the convenience store; you just throw it away when your numbers don’t pop up on the TV that night.

On the other hand, drafting Jamaal Charles in the first round is like buying a $10,000 raffle ticket with the potential to win a new Ferrari. It could end up great, but if he fails to live up to expectations, you may be walking away with a Ford Taurus. It’s going to sting more to lose on the gamble with the higher cost to enter, but it’s more than worth it if you get lucky and pick the right ticket.

Conversely, some players are like savings accounts. You put in your money, and at the end of the season, you get back what you put in. Sure, there’s a chance that your bank may boost the interest rate and you’ll wind up with a few more dollars in the account, but you’re not going to make a massive profit off of your savings account.

The perfect example here is Ray Rice. The Ravens back is like a government-insured, low-risk savings account that will keep your investment safe and sound for 16 games, with no disappointing collapses or thrilling gains.

During this series, I'll take a few pairs of players who are on opposite ends of this risk spectrum, and allow you to decide over the course of your draft if you want to play it safe, or take more of a risk.

Savings Account: Alfred Morris, Lottery Ticket: Jamaal Charles

As I mentioned above, Charles is definitely one of the riskier picks in drafts this year, and that’s mainly due to his weekly volatility. Alfred Morris, on the other hand, is one of the safer weekly bets. And we can better define the safety and volatility of these players using the Confidence Interval in the numberFire projections.

The Confidence Interval, or CI, is the range of possible outcomes that the projections are 68% confident the player’s final score will fall within in standard, non-PPR leagues. In other words, it’s the reasonably certain range of outcomes based on the algorithms and mathematics that go on behind these scenes when the system produces the projected statistics for each player.

This range isn’t as volatile for some players as it is for others, and the first glaring example at the running back position is between Charles and Morris.

Our projections see Charles and Morris having very similar seasons, with Charles (8th) coming in just ahead of the Redskins runner (9th). You might be thinking that’s a bit low for Charles, and you’d be right when comparing him to most other projections and ADP lists. But there’s a reason for Charles’ low ranking: Volatility.

When comparing the lowest value for both running backs within the Confidence Interval metric, you find that Charles actually has a lower floor than Morris. And that’s because Morris was more efficient last year than Charles, and the projections expect that to continue in 2013.

Among running backs with 200 carries or more, Morris finished 7th with a net expected points value per rush of 0.03. This NEP value calculates the amount of real football points a player adds to his offense in terms of field position gained and lost by his performance. What this specific NEP is saying is that Morris added .03 points every time he touched the football last year as a rusher, contributing positively towards his team's overall output.

On the season as a whole, Morris had a total rushing NEP of 10.85, which was sixth among the same qualified group of 200 carry runners. To boil that down, Morris added almost 11 points of value to the Washington offense, which is significant for a running back.

Compare that to Charles, who had an NEP per rush of .01, and a total NEP as a runner of 2.7 for the season. Charles had a decent amount of carries in Kansas City, and it amounted to a significantly lower total added value.

In terms of fantasy, these numbers can often times correlate nicely to future fantasy success. You can have a high NEP per touch if you rarely carry the football, but in the case of these two backs, that's clearly not an issue. Essentially, Morris was just better on the ground last season than Charles.

Part of the reason Charles is ranked ahead of Morris in the rankings, however, is because Charles added much more as a pass catcher. But it’s his lower efficiency at performing “Job Duty #1” at running back which makes him a more volatile selection in your fantasy drafts.

Keep in mind that this volatility can play to your favor as well. The Chiefs will not have such an awful situation at quarterback this season, and they'll have a new head coach who has worked wonders with offenses in the past. So Alex Smith and Andy Reid are just part of the reason that Charles might be worth the risk for you, if you want to take a bit of a chance.

Now, remember how I said that Charles’ lowest possible outcome using CI was lower than Morris’? That comes with a high CI value that ranks sixth among running backs, ahead of Marshawn Lynch and Trent Richardson, who slot in ahead of him on numberFire’s rankings based on average projections.

So there is a mid-first round to late-first round swing from Charles lowest value to his highest value. And if you believe that a better head coach and a more stable quarterback will result in a more reliable Jamaal Charles, you are thinking like the top half of his Confidence Interval projections, and you might just be rewarded as such.

But if you’re concerned about his injury history, his inconsistent usage in the past, and his general “boom or bust” nature, you’re thinking with the lower part of his CI projections, and you’ll probably avoid him as his draft position will usually be higher than your perceived value for him. If you want to take a chance on this lottery ticket, however, you might just hit it big, because he can outperform his projections with his incredible athletic ability.

Morris, on the other hand, has a floor and a ceiling that find him either 8th or 9th among running backs, meaning he’s a solid value at the end of the first round. That's typically where you can get him in virtually every draft you’ll enter this summer. He’s a savings account; you’re going to get back what you put in, with maybe a little extra.

So take the gamble, or play it safe. Either way, you're going to get a fantastic fantasy running back. But is the upside worth the potential loss of value? That's all dependent on how you choose to build your team.