I find Curtis Granderson’s career trajectory – or career trajectories, for that matter – incredibly fascinating, possessing an almost chameleon-esque quality. He’s looked like a Hall of Famer in one season (2007, when he slugged .302/.361/.552 with 38 doubles, 23 triples, 23 home runs, and 26 stolen bases en route to totaling 7.9 fWAR) and barely above league average two years later.

He once swiped eight bags in 13 tries in one season, followed that up with Tim Raines-esque efficiency by going 26-for-27 the next year, and then went a mediocre 12 out of 16 the following season. And then there’s his development into a genuine middle-of-the-lineup, 40-HR power bat which, admittedly, was more than aided by Yankee Stadium’s friendly right field porch.

But Granderson’s swing-and-miss ability, sometimes porous while other times average, has placed in him some rarefied company.

Since the beginning of the Live Ball Era in 1920, four players have struck out in at least 28% of their plate appearances in one season and 18% or less in another, separate campaign (250+ PA): Dan Uggla, Jason Kubel, Josh Hamilton, and Curtis Granderson.

Let’s take it one step further: Since the start of the Live Ball Era, there are nine instances when a hitter has fanned in at least 26.5% of his plate appearances during his age 31 and 32 seasons (200+ PA): Adam Dunn, Carlos Pena, Jack Cust, Jose Hernandez, Kelly Shoppach, Miguel Olivo, Mike Napoli, Rob Deer, Ryan Howard, and, of course, Granderson.

But Granderson’s evolution didn’t stop there. Not even close.

Of those nine players, no player was able to take a larger step forward in terms of decreasing their respective strikeout rate during their age-33 season than Granderson, who fanned 28.4% between 2012 and 2013 but improved all the way down to 21.6% last season.

Below is a chart of combined strikeout rates for each player’s age-31 and -32 seasons and his rate the following year:

Player Age 31 & 32 Age 33 Improvement Curtis Granderson 28.4% 21.6% +31.5% Adam Dunn 34.9% 31.1% +12.2% Carlos Pena 27.7% 26.6% +4.1% Jack Cust 30.8% N/A N/A Jose Hernandez 31.8% 31.0% +2.6% Kelly Shoppach 33.7% 36.2% -6.9% Miguel Olivo 27.5% 26.3% 4.6% Mike Napoli 29.7% N/A N/A Rob Deer 30.6% N/A N/A Ryan Howard 29.0% 30.0% -3.3%

Notes: Shoppach made only 127 trips to the plate during his age-33 season. Mike Napoli is entering his age-33 season. Deer didn’t appear in a game for three years following his age-32 season.

Two things:

1. Now did this improvement in his strikeout rate directly correlate to an improved performance? Not exactly. Granderson posted a 111 wRC+ between his age 31- and 32-seasons and a 105 wRC+ the following year.

2. How did he make such a drastic improvement? Well, according to FanGraphs’ Pitchf/x plate discipline, Granderson swung at fewer pitches outside the zone (28.4% vs. 26.7%) and he made far more contact on pitches outside the zone (53.4% vs. 59.5%).

In the end, in terms of production, Granderson had a nice, decent year in 2014. But his improvement in his strikeout rate is just the last fluctuation in his long career.

. . .

Shameless Plug: Check out Joe's book, The 2015 Prospect Digest Handbook, here.



