George Santayana was a renowned poet, essayist, and philosopher in his time, one whose legacy extends far beyond a simple phrase that would fit on a fortune cookie. However, he is best remembered not for his treatises or novels, but for this aphorism: “Those who cannot remember the past are condemned to repeat it.”

History applies just as much to playbooks as it does to textbooks, and so we need to check our chapters when we scope out this year’s purportedly historic running back draft class.

The 2017 NFL Draft has been heralded for a while as having a full catalog of NFL backfield talent, and it does appear there are quite a few compelling options for rush-hungry football teams. But how does this stack up against those in recent history?

Will the 2017 running back class be a series of instant classics, or are they just a dime a dozen?

The Best of Times, The Worst of Times

The run-up to the NFL Draft is annually both a season of light for the premier talents who are ready to make the leap from college to pro football, and a season of darkness for those who fall just short.

Every year in the spring, of course, one of the main events is the NFL Combine -- where hopefuls get poked, prodded, timed and tested every which way. By comparing recent running back classes’ athletic acumen based on Combine measurements, we can find out which group of runners is above the rest.

To do this, I’ve examined a metric called “Speed Score”, with a formula concocted by my friend at Fake Pigskin, Jay Holmes. Speed Score is way to adjust the 40-yard dash for a player’s weight; a heavy player running a 4.50 is more impressive than one at a lighter weight, and the score reflects this.

When we compare these players to the total 512 running backs to participate in the Combine since 1999, how do their athletic gifts match up?

The table below lists the 19 running backs in the 2017 class with over a 100.0 Speed Score, and their rankings by Speed Score against the rest of recent Combine history.

Let’s begin the analysis with a caveat: there is much more to being a running back than straight-line speed, and some believe agility in tight spaces is much more of an important quality than pure velocity. For our sake, though, the 40-yard dash is the most consistently tested metric available, and almost all running backs have even projected times for us to gauge them against others here.

It’s clear that 19 backs with over a 100.0 Speed Score is pretty darn impressive, but when we compare the top tier of this class in Speed Score, there have been much more impressive years.

In the “elite” group, eight other years outclassed this year’s runners. A sturdy top-three of Chris Johnson, Darren McFadden, and Rashard Mendenhall (all 119.0 or higher) was produced in 2008, while 2010 was next-best with Ben Tate (fourth-highest ever), Ryan Mathews, and C.J. Spiller. Even 2005 had Brandon Jacobs (fifth), Ronnie Brown, and Eric Shelton.

However, when we expand to the top 10, the 2017 class scoots up to a solid sixth place. The aforementioned classes still outpace them, but only 2011 (Roy Helu and DeMarco Murray) and 2009 (Andre Brown and Cedric Peerman) joined them.

The strength of this class isn’t in the top-end quality of it, but in the depth of the serviceable running backs available.

When we set a 100.0 Speed Score as the minimum threshold and see how many backs meet this mark, the 19 this year are second-most in nearly two decades. Only 2011 had more (20) than this year, and their variety of options seem to be a good comp for this year’s group.

Out of the 19 running back classes since 1999, 2017’s elite athletic quality is middling, the high-end is just good, but the depth is outstanding.

Oh, The Places You’ll Go!

No one can contest that the 6’0”, 233-pound frame of Texas' D’Onta Foreman is an imposing sight barreling through a gap in the offensive line, and no one wants to get in between Louisiana State's (LSU) Leonard Fournette and the end zone due to his absurd size/speed combination.

But part of what makes a prospect class historic is what one does with their talents, not just the talents themselves. We can’t crown this the “best” running back class in the last two decades without also assessing the production they’ve lined up in college.

I looked at the 192 running backs to accrue at least 600 career rushing attempts in college since 2002 (the furthest back Sports-Reference.com has data), and ranked each player by career rushing yards per attempt and rushing touchdown rate. By looking at the average ranking of the 10 best running backs each year, we can see which class statistically is supreme.

The table below shows 2017’s 10-best producers on the ground.

There are 11 running backs from the 2017 class ranked in the top 25 of the 192 running backs to top 600 carries in their NCAA careers -- a stunning feat.

There should be no surprise that Florida State's Dalvin Cook and Fournette lead the way, but Oklahoma's Samaje Perine and Toledo's Kareem Hunt -- among others -- also stacked the box score during their time in college. Of the 20 running backs in this year's class to see that many carries, 17 had rushing yards per attempt rates over 5.00 and 14 had touchdown rates over 5.00 percent to boot.

This kind of prowess across the board is telling somewhat of a more fast-paced offensive era, but when nearly half of the top tier of these players comes from this one class, it’s pretty easy to say they are one of the top classes in recent memory.

No other class comes close to the ridiculous production of these players, and that’s without Stanford standout Christian McCaffrey’s true talent -- receiving -- even being factored in.

The 2017 class has some flaws, but the biggest strength they possess is their depth and variety of skills. There is no one clear top running back in this class, and there shouldn’t be; each one brings a unique skillset, and each one of this deep class deserves at the very least a long look in the draft process -- both for NFL teams and fantasy football owners alike.

This may be a year in fantasy leagues to not draft the elite talent at the running back position highly, but invest in the middle rounds in a back or two with a good situation. You never know: you might find yourself on the right side of draft history if you gamble correctly.