Receivers changing teams

I devoted a recent article to Keyshawn Johnson's effect on the running game of the Jets and the Bucs. Let's now turn our attention to the man himself. What happens to receivers who change teams in the offseason?

First, some big news: I recently expanded my database. It now contains (very nearly) complete career data for every QB, RB, WR, and TE active in the NFL at any point after 1993. That comes to about 950 players and over 4500 player-seasons. In particular, I've got 73 different WRs who have at one point scored 140 or more fantasy points in a season (my cutoff for "legitimate fantasy starter"), and those 73 combined to accomplish that task 177 times. So we shouldn't have any problem finding some guys who were in situations similar to Keyshawn's current one, right?

Wrong. Even with all that fresh new data, it seems that there is very little precedent for a receiver of Johnson's caliber changing teams in the offseason. I rounded up a list of all WRs who scored 140 fantasy points, and then played for a different team the following year. I only found 10:

                                   |-- YR1 --||-- YR2 --| 
LastName     FirstName      YR1 AGE   TM  FPT    TM  FPT
---------------------------------------------------------
Alexander    Derrick       1997  26  bal  155   kan  123 
Brooks       Billy         1995  31  buf  142   was   22 
Early        Quinn         1995  30  nor  157   buf  104 
Emanuel      Bert          1997  27  atl  153   tam   76 
Graham       Jeff          1995  26  chi  154   nyj  115 
Ismail       Raghib        1998  29  car  150   dal  146 
Martin       Tony          1998  33  atl  154   mia  134 
Miller       Anthony       1993  28  sdg  158   den  141 
Rison        Andre         1994  27  atl  157   cle   88 
Thigpen      Yancey        1997  28  pit  182   ten   67 
Everything there should be clear: FPT is fantasy points. AGE is the player's age during the first season (by the way, in this and all my other studies, I'm defining a player's age to be his age as of December 31 of the given year).

First things first: as you can see, this group's production went in the tank big-time after they switched teams. They went from an average of 156 fantasy points to 102, a decline of 35%. All ten saw their fantasy points drop. By now, you should have been expecting an overall decline, but maybe not that big.

To get a frame of reference, we take a quick look at all WRs who scored over 140 fantasy points in a given year. Here's the breakdown, with the above numbers repeated for comparison:

                                YR1      YR2   
Category              Number    FPT      FPT    CHANGE        
-----------------------------------------------------
All WRs over 140       147      176      141     -20%        
over 140 / changed tm   10      156      102     -35%   

                               ------- the next year ----------
Category              Number   Improved   Declined    0eclined
---------------------------------------------------------------
All WRs over 140       147        33         114         78%
over 140 / changed tm   10         0          10        100%
This doesn't bode well for Keyshawn, but I'm not ready to slide him down my draft list -- not yet anyway. Looking at the list above, we really don't see many guys who are truly comparable to Johnson. Brooks, Early and Martin were all on the wrong side of 30 when they changed teams (Johnson was 27 last year), and of the others, only Rison and maybe Miller had a track record as good as Keyshawn's. The others were either inconsistent or coming off their first good season.

Bottom line: there are just not enough examples of high-quality WRs changing teams to get a good read on Keyshawn's fate. What little evidence there is suggests that Keyshawn is in for a rough year, and that's without even taking into account the run-first nature of the Bucs' offense. All that said, I'm ignoring the data and rating Keyshawn higher than most. Call it a hunch -- even hard-core number-crunchers are allowed to use those from time to time.

Let's now turn to the more general question. What about all the other, more ordinary, WRs who changed teams? Is there a general trend that might tell us something about Shawn Jefferson and Bert Emanuel and Curtis Conway?

I'm just a little surprised to say that the answer appears to be yes. To get a data set as large as possible, let's lower our cutoff to 60 fantasy points. With the lower standards, we can now find gobs of receivers who changed teams -- 91 of them, to be exact. Here is the breakdown:

                                YR1     YR2   
Category              Number    FPT     FPT    CHANGE        
-----------------------------------------------------
All WRs over 60        589      117      102     -13%        
over 60 / changed tm    91       99       67     -32%   

                               ------- the next year ----------
Category              Number   Improved   Declined    0eclined
---------------------------------------------------------------
All WRs over 60        589       208         381         65%
over 60 / changed tm    91        16          75         82%
A much sharper decline for the receivers who changed teams. But wait, there's more to the story. As it turns out, the team-switchers tended to be older as a group than the non-switchers. The average age of the movers was 29.3, and the average age of the entire group was 27.8, which means the decline could be at least partly due to age and not the change of scenery. To correct for this, we give one final breakdown, focusing in on only receivers aged 26-28 (in the first year):
                                            YR1     YR2   
Category                         Number     FPT     FPT    CHANGE        
-----------------------------------------------------------------
over 60 / age 26-28                209      119      104     -13%        
over 60 / changed tm /age 26-28     39       98       71     -28%   

                                        -- the next year --
Category                           No.   Imp   Dec   0ec
-----------------------------------------------------------
over 60 / age 26-28                209    74   135   65%
over 60 / changed tm / age 26-28    39     8    31   79%
The result is still just as clear. It does appear that receivers who switch teams are more likely to bite the dust than receivers who don't, and this squares with conventional wisdom. Maybe it takes awhile for WRs to learn the new system, or maybe this means that, in general, the teams that let these receivers go knew what they were doing.