Ever wonder what goes into being the NFL rushing champion? When exactly does he gain his yards? How is he used by the coaching staff?

Let’s find out by crunching the numbers for the Eagles’ LeSean McCoy, whose 1,607 yards last season gave him the title by a comfortable 268 over the Bears’ Matt Forte. As you’ll see, McCoy’s down-and-distance breakdown tells us much. (Note: The figures listed in the downs columns are attempts-yards-touchdowns.)

To summarize:

● McCoy gained 69.8 percent of his yards (1,122) on either first-and-10-or-more or second-and-10-or-more — both good running downs, you might say.

● In those two situations, he averaged 5.7 yards a carry (196/1,122). In all others, he averaged 4.1 (118/485).

● He wasn’t much of a factor on third and fourth downs, where the game is often won. Totals: 42 carries, 174 yards, 0 touchdowns.

Even in a spread offense, against defenses less compact, Eagles coach Chip Kelly still picked his spots with McCoy. Nearly two-thirds of the time (205 of 314, or 65.3 percent, counting nine rushes on third-and-5 or longer) he called on him in circumstances favorable to a running back. Indeed, LeSean had more attempts on second-and-10-or-more (48) than on third and fourth downs combined (42). That’s how you average 5.1 yards a carry. As that old play caller, Sun Tzu, said, “The worst policy of all is to besiege walled cities.”

The Eagles had the best pass-run balance in the league, too: 508 passes, 500 rushes. But McCoy’s stats suggest Kelly ran the ball, as much as anything, to keep the defense honest — read: more vulnerable to the passing game — not to pound the opponent into submission (as in days of old).

Check out McCoy’s performance against the Redskins in Week 11. That might be the best illustration of what I’m talking about. He carried 20 times for 77 yards and two touchdowns in a 24-16 Philly win, but Washington almost totally shut him down. So how did Shady average nearly 4 yards an attempt? Answer: By taking handoffs on third-and-21, second-and-20, first-and-20, second-and-19, second-and-16, first-and-16 and second-and-10. On those seven runner-friendly plays, he gained 67 yards. On his other 13 he gained 10 — 27.7 inches a pop.

Read into this data what you will. To me, it’s just more evidence of the Marginalization of the Running Back. Especially when you consider that none of the last six rushing leaders even managed to win a playoff game — and three failed to make it to the postseason. The specifics:

HOW THE LAST SIX RUSHING CHAMPS FARED IN THE POSTSEASON

Sources: NFL gamebooks, pro-football-reference.com