Where will they be in 4 years?

This is just a quick little study for all of you who are trying to decide on your keepers right now, or wondering whether you should package up two or three good solid players for that one young mega-stud.

Things happen fast in the fantasy football world. Top producers can become useless benchwarmers (and vice versa) with very little warning. If you have a top-notch player right now, what are the chances he'll still be top-notch next year? In two years? Three? For those of you in salary/keeper leagues, is a four-year contract ever a good idea?

To try to get a handle on these kinds of questions, I looked at the top two quarterbacks, the top five running backs, the top five wide receivers and the top two tight ends of every season from 1985 through 1996. Then I tracked those players for their next four seasons. As usual, my metric is fantasy points, defined by

Here are the results, first for the running backs:
+-----------+
| Top 5 RBs |
+-----------+
Number of years later           Median rank
--------------------------------------------
         1                          6
         2                         12.5
         3                         16
         4                         28
Here's what it means. If you take the top five running backs from a given year, and then you look at where they rank the next year, you'll find that half of them will be above 6 and half below 6. So a randomly selected top five RB has a 50/50 shot of being a top 6 RB next year. In two years, he's got a 50/50 shot of being a top 12 RB. Three years later, he's even money to be in the top 16, and in four years, 28th is a fair over/under on where he'll rank.

In some sense, this says that RBs are fairly stable. From one year to the next, the studs are reasonably likely to remain studs. On the other hand, it shows just how quickly things can change. A generic top five RB is more than likely a fantasy backup (at best) in just four years. Here is the WR data:

+-----------+
| Top 5 WRs |
+-----------+
Number of years later           Median rank
--------------------------------------------
         1                          11
         2                          15.5
         3                          26.5
         4                          37.5
So a randomly-selected top five WR is likely to be a fantasy benchwarmer in three years and a fantasy free agent in four.
+-----------+
| Top 2 TEs |
+-----------+
Number of years later           Median rank
--------------------------------------------
         1                           4
         2                           5
         3                           8.5
         4                          15.5

+-----------+
| Top 2 QBs |
+-----------+
Number of years later           Median rank
--------------------------------------------
         1                           5
         2                           5
         3                           9.5
         4                          10
Top QBs seem to be able to hold some value for the longest time. Even four years later, a top two QB is likely to still be a fantasy starter.

But wait, you say, the guy I'm thinking of signing to a four-year deal is young, so he's got a better chance than a "typical" top player. That's probably true. Let's try to see just how much better. I'll run the exact same study, but this time I'll limit my attention to top players who were 25 or younger.


==================
YOUNG PLAYERS ONLY
==================
+-----------+
| Top 5 RBs |
+-----------+
Number of years later           Median rank
--------------------------------------------
         1                           4
         2                           7
         3                           8
         4                          13

+-----------+
| Top 5 WRs |
+-----------+
Number of years later           Median rank
--------------------------------------------
         1                           8.5
         2                           9.5
         3                          11
         4                           9.5

+-----------+
| Top 2 QBs |
+-----------+
Number of years later           Median rank
--------------------------------------------
         1                           5
         2                           4.5
         3                          12
         4                           8

+-----------+
| Top 2 TEs |
+-----------+
Number of years later           Median rank
--------------------------------------------
         1                           2
         2                           4
         3                           5
         4                           5
First a warning: we're getting down to sample sizes here that are pretty small. For instance, there were only eight QBs who were in the top two in a given year and were 25 or under, so those numbers shouldn't be taken too seriously. Anyway, they're worth taking a quick look at.

At all positions, it looks like your under-26 stud is likely to at least be a legitimate fantasy starter for the next four seasons. On the other hand, it is not necessarily reasonable to expect him to continue to be a stud for any length of time.

Data