Discovering The True B.J. Upton
In order to understand which of the seasons Upton had that can best be reconciled with his other ones, I separated each of his individual seasons and then compared them to the rest of the seasons to determine how similar the two data sets were to each other. For example, for Upton's 2004 season, I compared his 2004 numbers to the totals of his 2006-2010 seasons.
There have been two seasons in Upton's career which in no way reflect what kind of hitter he is. The first season is 2006 where in fifty games, Upton hit a measly .246/.301/.291 with a .209 GPA and .279 wOBA, far below what Upton has hit in his other 562 games where his batting line is .263/.351/.420 with a .263 GPA and .354 wOBA.
No matter how poor of a player I might think Upton is, he is definitely not as bad as he was in that fifty-game stretch.
Then again, Upton is nowhere near as great as he was in 2007. Most people point to this career year of Upton as evidence of the player he could or should be, forgetting that even an average player can have one really phenomenal season. The truly elite players are able to string together a number of great seasons.
Upton has failed to do so in a big way. During his career year, Upton hit .300/.386/.508 with a .301 GPA and a .396 wOBA, statistically significantly more impressive than .252/.336/.383 with a .247 GPA and .336 wOBA he hit in all other games.
Upton's 2007 season was an extremely lucky for him, which explains why he has not been able to duplicate it. First of all, he had an extremely high batting average on balls in play compared to his career. That season, it was .393, much higher than his career mark of .335, which is only that high because it includes his 2007 season.
Also, Upton was lucky when it came to his home run to fly ball ratio. Once again, his 2007 mark of 19.8% of his fly balls leaving the park is almost twice as much as his career home run to fly ball ratio of 10.1%. That explains why his slugging percentage was so out of line with his slugging percentage in other years.
To a lesser extent, 2008 also represented a season where he outperformed his true self, at least in one category; every other category was in line with his combined other seasons. His on-base percentage of .383 during the 2008 season is significantly better than his .335 on-base percentage in his other seasons combined. Upton is simply not a player who will consistently have an on-base percentage that high.
He was helped in large part that year by drawing an inordinate number of walks. His walk percentage (walks per plate appearance) that year was 15.2%; in all his other games, it is only 10.0%. Once again, we see Upton fails to match himself and exhibit some consistency when he reaches great heights.
Taking all his seasons and comparisons into consideration, it is safe to assume Upton is a player whose on-base percentage will be within a few ticks of .335, his slugging percentage will be within a few ticks of .405 and his wOBA should hover around .340, combining to make Upton a perfectly average hitter.
Despite what Upton has the potential to do on the baseball field, his production should have the final say and his production says he will never be a star in the majors. He is the average player he has been for his career.