In limited action last season, Zach Ertz put up historical numbers for a rookie tight end, priming him for a coming out party in 2014.

Zach Ertz led all rookie tight ends in receiving touchdowns last season (5), and likely hasnâ€™t even scratched the surface of his potential.

The reason? He hasnâ€™t played enough snaps to establish himself quite yet. Of the Philadelphia Eagles' 1,128 offensive snaps, Ertz was only on the field for 459 of them a season ago, or around 40 percent. But make no mistake - Ertz is a ticking time bomb, and he may just explode in 2014.

Get this guy on the field and heâ€™s going to make plays, no questions asked. The numbers prove it.

Let me explain.

At numberFire, we use an advanced metric known as Net Expected Points (NEP) that tracks the total number of points a player either adds or subtracts from his teamâ€™s expected total through the course of the season. You can read more about it here. To analyze Ertzâ€™ metrics from last year, weâ€™ll look specifically at Reception NEP, which is the number of expected points a tight end gets on receptions only.

Ertz was targeted 57 times in 2013. Among tight ends that shared a similar volume of opportunities (37 to 77 targets), Ertz ranked ninth in Reception NEP. Thatâ€™s pretty impressive for a rookie who didnâ€™t score a touchdown until Week 9.

However, it was clear that Ertz wasnâ€™t quite ready to see a significant number of snaps until the second half of the season. According to Tim McManus of Birds 24/7, Ertz played 45 percent of the snaps during the second half of the regular season, compared to only 36 percent in the first eight games. Also, 22 of his 36 catches came in the second half of the year, as did his five scores.

Just how good was Ertz in those final eight games? Letâ€™s investigate.

Ertzâ€™s Second Half

Ertz finished with a Reception NEP of 36.73 for the entire season. His Reception NEP in his final eight games totaled 25.69, which accounted for about 70 percent of his production. That's astounding, really - almost three-quarters of his production came in half of the NFL season.

If we extrapolate his Reception NEP in the final eight games to a full 16-game season, Ertz would rank fourth amongst tight ends that saw a similar volume of opportunities. Those numbers donâ€™t even include his three catches and a touchdown in the Eaglesâ€™ playoff game.

Again, thatâ€™s pretty amazing for a rookie tight end. However, letâ€™s take this one step further and analyze how Ertzâ€™s first year in the NFL compared to other top tight ends in their rookie season.

Ertz Versus Historical Rookie Tight Ends

Jimmy Kempski of Philly.com wrote an awesome article illustrating how Ertz had the second-best statistical rookie season for a tight end compared to the rookie years of the top 15 tight ends from 2013 (in terms of total receiving yardage).

For comparison, I decided to analyze how numberFireâ€™s metrics viewed Ertzâ€™s rookie season using the same criteria. Below is a list of the top-15 tight ends in Reception NEP in 2013. This chart illustrates their Reception NEP in their rookie seasons, in order from highest to lowest:

Player Reception NEP Tim Wright 56.88 Rob Gronkowski 56.71 Jordan Reed 55.85 Zach Ertz 36.73 Jimmy Graham 36.46 Greg Olsen 32.39 Jason Witten 32.19 Antonio Gates 30.72 Martellus Bennett 27.35 Charles Clay 19.42 Vernon Davis 17.97 Delanie Walker 1.23 Jordan Cameron 0.78 Scott Chandler 0.58 Julius Thomas 0.17

As you can see, Ertz finished fourth on a list that consists of many decorated players that have been among the best at their position for a number of years.

Note: Tony Gonzalezâ€™s rookie season is not included in this list because our data mostly dates back to 2000. Nevertheless, Ertz outperformed Gonzalez in his rookie year by accumulating three more catches, 101 more yards, and three more touchdowns.

Now that Ertz has a full year of experience under his belt, he will absolutely have more opportunities in 2014. His head coach said as much back in May:

â€œI think Zach can have a huge role,â€ Chip Kelly told Jeff McLane of the Philadelphia Inquirer.

Again, put Ertz on the field and heâ€™s going to put up numbers. He demonstrated that by posting historical statistics his rookie year, and his potential is through the roof for his sophomore season.