History says DeMarco Murray's incredible season is likely to decline down the stretch

At the beginning of the season, it appeared as though the Eagles were the clear odds-on favorite to win the NFC East, mainly due to a perceived weakness in their division rivals. So far, the Giants (3-4) and Redskins (3-5) have cooperated, but the Cowboys (6-2) have been one of the biggest surprises of the 2014 season.

The biggest reason for the Cowboys' success has been their #1 ranked rushing offense, led by DeMarco Murray, who is having an MVP-caliber year. Through the first half of the Cowboys' season, Murray leads the NFL with 1,054 rushing yards and seven touchdowns. He has also run for a very impressive 5.1 yards per carry and 51 first downs. By comparison, the Texans' Arian Foster is second in rushing yards with 766, and Matt Forte is second in rushing first downs, with 35.

The Cowboys' ball control rushing attack has kept their undermanned defense off the field, and they've piled up wins as a result. However, Murray has racked up an inordinate number of rushing attempts. Through eight games, the Cowboys have run Murray 206 times, which puts him on pace to finish second all time in single season rushing attempts.

Below is a list of the top 12 single season rushing attempt leaders in NFL history. It has been well established that the runners listed below saw their careers take a sharp decline after their extreme workload seasons. While the Cowboys are potentially damaging Murray's long term career, I have not seen a comparison of those extreme workload seasons, in terms of the first half of their high workload seasons vs the second half. The list (click here to enlarge):

Only three of the 12 runners listed above had a better yards per carry average in the second half than they did in the first half. Furthermore, two of the three had very low yards per carry totals the first half of the season. In 1984, James Wilder rushed for just 3.74 YPC in the first half of the season. In 2003, the Dolphins' Ricky Williams ran for a minuscule 3.35 YPC. There was nowhere for them to go but up.

Conversely, the players on the list above who rushed for at least 5.0 YPC all had severe dropoffs the second half of the season. See below (click here to enlarge):

Murray would of course fall into that category, as noted earlier that his current YPC is 5.1.

While Murray has been absolutely tremendous so far in 2014, history says his production is likely to fall off from here on out.

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