There have been two notable cases of it this year: Jameis Winston and Marcus Mariota. Winston was selected to the Pro Bowl last year, and Mariota had a solid rookie year as well. However, both players have regressed in Year 2. Why do some players take a step back in their second year? Shouldn't they improve as they gain more pro experience?
I pulled the numbers on the notable "sophomore slumps" in the past 10 seasons, sticking to QBs only. Limiting myself to QBs allows me to use "QB Rating" to quantify their performance in each year (and more imporantly, compare each player to the average for that year).
|Player||Team||Year||QB Rating Year 1||QB Rating Year 2||Difference|
|Robert Griffin III||WAS||2013||102.4||82.2||-20.2|
On average, these QBs' rating fell almost 9 points from Year 1 to Year 2. What if we compare each player's performance to the average QB rating in each year?
|Player||Team||Year||QB Rating Year 1||QB Rating Year 2||Difference||vs Avg Year 1||vs Avg Year 2|
|Robert Griffin III||WAS||2013||102.4||82.2||-20.2||16.5||-5.2|
These rookies were slightly above average in their first year, but do indeed check in well below average in their second year. This would seem to imply there is indeed regression and the "sophmore slump" is real! BUT...
|Player||Team||Year||QB Rating Year 1||QB Rating Year 2||Difference||vs Rookie Avg Year 1||vs 2nd Year Avg Year 2|
|Robert Griffin III||WAS||2013||102.4||82.2||-20.2||25.7||1.8|
The key word here is regression. Regression to the mean. In Year 1, this set of QBs was almost 12 points above the rookie average, but in Year 2, they simply regressed to the mean (almost literally, to less than 1 point below the 2nd Year average). This "sophmore slump" is real in the sense of declining year-over-year, but is simply another way of describing regression to the mean.