Last off-season, I started grading the most dominant running back seasons in NFL history. I ended up writing five posts, which are available here:
While I'll certainly tweak the formula later this off-season or next year, I was curious to see how Chris Johnson's incredible 2009 performance would rate. Johnson not only rushed for 2,000 yards last season, but he also set the single season record for yards from scrimmage. So how great did Johnson's season end up being? And which RB was #2 in 2009?
Here's a review of the formula, at least for seasons since 2002. We break each player's stats down into three categories: rushing, receiving and scoring.
Step 1: Calculate the player's rushing score by taking his total rushing yards, subtracting 25 yards for all fumbles and adding 25 yards for all fumbles recovered. Divide that result -- the player's adjusted rushing yards -- by his number of games played.
Step 2: Start with the player's total receiving yards, add 1.5 adjusted receiving yards for each reception, and divide by games played.
Step 3: Add up the player's rushing and receiving touchdowns and divide by his number of games played.
Step 4: Now each RB has a grade in rushing, scoring and catching. Now we compare their production in that category to the league average. The league average is defined as the average production of the top 32 RBs in the league (in that specific category), but after removing the RB in question from the league average. So all o the top 32 RBs in any of the three categories will be compared to the other top 31 RBs in that category.
Last year, the top 32 RBs by adjusted rushing yards averaged 67.2 adjusted rushing yards per game (with the adjustment being just for fumbles). The top 32 RBs in scoring per game averaged 0.66 TD/game. The top 32 RBs in adjusted catch yards averaged 27.7 ACY/G. So a RB that played in 16 games would need to have more than 1,074 adjusted rushing yards, 10.6 total TDs or more than 443 adjusted receiving yards to get credit for being "above average". Because we're looking to find the most dominant RBs, only above average performance is going to be rewarded. There's nothing dominant about 1,000 rushing yards. A penalty is then given to RBs who missed games.
Once we have per-game averages in the three categories, and league averages in the three categories, we find how much each RB surpassed the league average. For rushing and receiving, we multiply the number of rushing and receiving yards above average by games played; for scoring, we do the same and then multiply each touchdown above average by 20. Add up all three categories, and that's the running back's score.
Johnson, of course, led all RBs by a large margin in adjusted yards gained over average. His 2009 season comes in at #10 all-time, tightly placed between Walter Payton's 1977 season and Terrell Davis' 1998 performance. Number two this year? Ray Rice, the only other player in 2009 to top 2,000 yards from scrimmage. Maurice Jones-Drew, Thomas Jones and Steven Jackson round out the top five. Vikings star Adrian Peterson checks in at #6, as his 7 fumbles (and no fumbles recovered) knocked him down the rankings.
Because of the nature of the formula -- it's used to grade the most dominant running backs -- it doesn't do a good job at separating out the 13th best running back from the 20th or 30th best at the position. It's very good, IMO, at separating out the second most dominant from the fourth most, but the formula is not a jack of all trades tool. The table below shows the top ten most dominant running backs from 2009:
Let's go through Johnson's score.
He rushed for 2006 yards, fumbled three times, and recovered once. That's a total of 1956 adjusted rushing yards, or 122.3 ARY/game (that's what the first column shows). The top 32 running backs in the league in ARY/G averaged 67.2 ARY/G, but that includes Johnson. The other 31 RBs in that category averaged 65.4 ARY/G, which means Johnson averaged 56.9 ARY/G more than the "average" running back in the league. Multiply that by 16 games and you get 910, which is Johnson's final grade in the rushing category.
Johnson caught 50 passes for 503 receiving yards, or a total of 36.1 adjusted receiving yards per game (the rec/g category). The top 32 RBs in adjusted receiving yards per game averaged 27.7 adjusted receiving yards per game. Subtract Johnson from the league average and multiply by 16, and you get 139, Johnson's score in that category.
Finally, Johnson scored 16 touchdowns in 16 games. The top 32 RBs in touchdowns per game averaged 0.66 total touchdowns per game, giving Johnson a small edge on the group. Minus Johnson, the other 31 runners averaged 0.65 TT/G, meaning Johnson averaged 5.6 more touchdowns on the season than the other top scoring running backs. Multiply that by 20, and add in Johnson's scores in the other categories, and you get Johnson's total value of 1161 yards over average.
Of course, this formula is far form a perfect indicator of running back value or running back talent or well, anything. It's influenced by a bunch of factors outside of a running back's control, just like every other statistic. The goal here is just to combine several of the key stats for a running back and see how dominant he was relative to the other top running backs in the league. Below are the top 16 running back performances in league history, under this metric:
|year||year||team||g||ARY/G||ACY/G||TT/G||RSH VAL||CAT VAL||TTD VAL||VAL|
This entry was posted on Tuesday, March 23rd, 2010 at 7:09 am and is filed under Best/Worst Ever, Running Backs. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.