Kris Bryant won the NL Rookie of the Year award.
Joe Maddon won the NL Manager of the Year award.
Who was more valuable to the Cubs 2015 season?
Bryant had a stellar 5.9 WAR. I previously calculated that Maddon's managerial WAR was 7.0. Bryant's WAR could have increased by .40 WAR if he was not held back at the beginning of the season. This is a bar debate with no correct answer.
How does Bryant compare to other Cubs ROY?
In 1961, Billy Williams won with a 1.2 WAR. His Hall of Fame career of 16 full seasons yielded a 63.5 WAR. This is the gold standard for Cub ROY winners.
In 1962, Ken Hubbs won the award with a replacement level zero WAR. This must have been a down year in the NL, because Hubbs led the league in strike outs. He must have been an exceptional defender. Tragically, he was killed in an accident and he only played 2 full seasons in the majors (with accrued 1.1 WAR).
In 1989, Jerome Walton won with a 1.9 WAR. He was one of the those "five tool" players that GMs at the time started to fawn over. Over Walton's 10 year ML career, he amassed only a 3.7 WAR.
In 1998, Kerry Wood won the award with a 3.9 WAR. The next year he was injured (an omen for his career), but in 14 seasons he did end with a 26.7 WAR.
In 2008, Geo Soto won the rookie award with a 3.3 WAR, which was unique because there were few power hitting catchers in the league. After 8 seasons, Soto has a 11.4 WAR. He is still an active major leaguer.
Bryant's rookie season (measured by WAR) was 4.9 times better than Williams' rookie year. Bryant's single season WAR is 9.2 percent of Williams' career WAR. Clearly, Bryant is the "best" Cub rookie of the year winner.
But as the list foretells, a ROY plaque does not mean a long or stellar career.
If you use 2.0 WAR as being a "starter" level, only Williams meets that standard. Wood is at 1.9 and Soto is at 1.425. That means one in five ROY winners have very good major league careers.
Bryant and the Cubs should be proud of the ROY achievement, but it does not mean Bryant will be guaranteed a Hall of Fame plaque in Cooperstown.
