How to Detect an Early Bust: FB% and It’s Importance

Before I get into how to detect an early bust in Fantasy Baseball drafts, I thought I’d share a story.

I’m at a weird age in my life. A few years ago I walked across a college campus and the girls that would flirt with me, if they weren’t my age, were at least close enough in age for it to be socially acceptable.

Fast Forward a Few Years: I walked into Target a couple months ago on my lunch break, looked up, and caught a mother and daughter, unbeknownst to each family member, as they checked me out: so weird.

I’m at weird age; I’m now old enough to where it’s socially acceptable for women of all ages to check me out.

It’s the same way for people from all walks of life. This reminds me of the study that looked at how often bystanders crossed the street, while they were at a yield sign and there was no through traffic. Or if they were prompted to do so by a homeless person, as opposed to a man in a suit. It’s safe to say that bystanders followed the man in the suit, but not the homeless person. (I can’t remember the name of the study or who conducted it, but I’d appreciate anyone who does know, if they could leave a comment about it). This video evokes the same sentiment:

The point is that appearances, even though they shouldn’t, determine how (some, not all) people approach you.

The same is true for Fantasy Baseball, but for better reasons.

Correlation Between FB% and Batter Outcome

Pitchers approach players that hit for more power differently. It’s a fact.

Since 2002, FB% (i.e. what percent of the time a player saw a fastball) had a -0.33r (chart below) with ISO (isolated power), which is a strong inverse relationship.

It makes sense — the more power a player has, the less you want to give him a pitch he can do damage with.

To take this a step further, it also makes sense that FB% has a -.42r (graph below) with K% (strikeout percentage), because players that hit for power, as a generalization, strikeout more.

A lot of this is old news. Eno Sarris has looked at potential breakouts based off of changes in FB%, and Robert Arthur has done the seminal research when it comes to the importance of a pitcher’s approach to hitters.

Importance in the Change of FB%

For my research, I looked at all qualified hitters that played in two consecutive seasons from 2002 to 2014. I then calculated the correlation between FB% from one season to next for that sample.

What I found is that FB% for hitters is very consistent from year to year. So much so, that it has one of the highest year-to-year correlations, at a .86r, of any metric for hitters! (See the chart below for the work that Bill Petti has done on year-to-year correlations for hitting metrics).

This suggests that once a hitter’s FB% changes, you can take this to be a meaningful variation.

Let’s look at the list below.

The fourth column shows the player’s FB% differential from 2013 to 2014. And the fifth column shows their difference in ISO from 2013 to 2014.

The list below is sorted to show the players that had the highest increase in FB% from 2013 to 2014 at the top, and, as you can see, the players who saw the highest increase in FB% saw some pretty drastic losses to their total ISO.

Season	Name	Team	FB% 13-14 (DIFF)	ISO 13-14 (DIFF)
2014	Ryan Howard	Phillies	9%	-0.079
2014	Curtis Granderson	Mets	6%	-0.099
2014	Allen Craig	- - -	6%	-0.042
2014	Ryan Braun	Brewers	5%	-0.089
2014	Hanley Ramirez	Dodgers	5%	-0.015
2014	Jason Heyward	Braves	5%	-0.097
2014	Robinson Cano	Mariners	5%	-0.063
2014	Jean Segura	Brewers	5%	-0.049
2014	Justin Upton	Braves	5%	0.02
2014	Evan Longoria	Rays	4%	-0.079
2014	Jose Reyes	Blue Jays	4%	-0.035
2014	Adeiny Hechavarria	Marlins	4%	0.008
2014	Andrelton Simmons	Braves	4%	-0.062
2014	Ben Zobrist	Rays	4%	-0.004
2014	Mike Trout	Angels	4%	0.04
2014	Domonic Brown	Phillies	4%	-0.108
2014	Casey McGehee	Marlins	3%	-0.053
2014	Todd Frazier	Reds	3%	0.013
2014	Jose Bautista	Blue Jays	3%	0
2014	Brian McCann	Yankees	3%	-0.021
2014	Asdrubal Cabrera	- - -	3%	-0.013
2014	Zack Cozart	Reds	3%	-0.048
2014	Dustin Pedroia	Red Sox	3%	-0.016
2014	B.J. Upton	Braves	3%	-0.083
2014	James Loney	Rays	3%	-0.041
2014	Matt Carpenter	Cardinals	3%	-0.06
2014	Justin Morneau	Rockies	2%	0.025
2014	Jimmy Rollins	Phillies	2%	0.054
2014	Freddie Freeman	Braves	2%	-0.008
2014	Jed Lowrie	Athletics	2%	-0.05
2014	David Freese	Angels	2%	0.004
2014	Jonathan Lucroy	Brewers	2%	-0.011
2014	Gerardo Parra	- - -	2%	-0.027
2014	Matt Kemp	Dodgers	2%	-0.042
2014	Starling Marte	Pirates	1%	0.001
2014	Dustin Ackley	Mariners	1%	0.051
2014	Chris Carter	Astros	1%	0.037
2014	Jay Bruce	Reds	1%	-0.06
2014	Ben Revere	Phillies	1%	0.006
2014	Giancarlo Stanton	Marlins	1%	0.036
2014	Adam LaRoche	Nationals	1%	0.03
2014	Derek Jeter	Yankees	1%	-0.056
2014	Coco Crisp	Athletics	1%	-0.066
2014	Chase Utley	Phillies	1%	-0.053
2014	Adrian Gonzalez	Dodgers	1%	0.038
2014	Hunter Pence	Giants	1%	-0.032
2014	Desmond Jennings	Rays	1%	-0.027
2014	Jason Kipnis	Indians	1%	-0.078
2014	Adrian Beltre	Rangers	1%	-0.025
2014	Chase Headley	- - -	1%	-0.02
2014	J.J. Hardy	Orioles	1%	-0.066
2014	Adam Dunn	- - -	0%	-0.027
2014	Dayan Viciedo	White Sox	0%	-0.014
2014	David Ortiz	Red Sox	0%	0
2014	Yunel Escobar	Rays	0%	-0.028
2014	Shin-Soo Choo	Rangers	0%	-0.046
2014	Chris Johnson	Braves	0%	-0.038
2014	Kurt Suzuki	Twins	0%	-0.053
2014	Aaron Hill	Diamondbacks	0%	-0.096
2014	Neil Walker	Pirates	0%	0.028
2014	Carlos Santana	Indians	0%	0.009
2014	Denard Span	Nationals	0%	0.013
2014	Brandon Crawford	Giants	0%	0.029
2014	Howie Kendrick	Angels	0%	-0.038
2014	Jhonny Peralta	Cardinals	-1%	0.035
2014	Jayson Werth	Nationals	-1%	-0.051
2014	Austin Jackson	- - -	-1%	-0.055
2014	David Wright	Mets	-1%	-0.081
2014	Elvis Andrus	Rangers	-1%	0.009
2014	Matt Dominguez	Astros	-1%	-0.047
2014	Alex Rios	Rangers	-1%	-0.036
2014	Anthony Rizzo	Cubs	-1%	0.054
2014	Jose Altuve	Astros	-1%	0.032
2014	Albert Pujols	Angels	-1%	-0.037
2014	Erick Aybar	Angels	-1%	-0.011
2014	Seth Smith	Padres	-1%	-0.026
2014	Omar Infante	Royals	-1%	-0.059
2014	Eric Hosmer	Royals	-1%	-0.019
2014	Yoenis Cespedes	- - -	-1%	-0.012
2014	Brett Gardner	Yankees	-1%	0.023
2014	Nori Aoki	Royals	-1%	-0.009
2014	Nelson Cruz	Orioles	-1%	0.054
2014	Andrew McCutchen	Pirates	-1%	0.038
2014	Garrett Jones	Marlins	-1%	-0.077
2014	Marlon Byrd	Phillies	-1%	-0.039
2014	Pablo Sandoval	Giants	-1%	-0.003
2014	Joe Mauer	Twins	-1%	-0.058
2014	Ian Desmond	Nationals	-1%	0.002
2014	Ian Kinsler	Tigers	-1%	0.009
2014	Miguel Cabrera	Tigers	-1%	-0.077
2014	Alcides Escobar	Royals	-1%	0.026
2014	Mark Teixeira	Yankees	-2%	-0.042
2014	Edwin Encarnacion	Blue Jays	-2%	0.017
2014	Alexei Ramirez	White Sox	-2%	0.039
2014	Josh Donaldson	Athletics	-2%	0.002
2014	Adam Jones	Orioles	-2%	-0.02
2014	Matt Holliday	Cardinals	-2%	-0.021
2014	Dexter Fowler	Astros	-2%	-0.052
2014	Torii Hunter	Tigers	-2%	-0.002
2014	Trevor Plouffe	Twins	-2%	0.027
2014	Chris Davis	Orioles	-2%	-0.139
2014	Aramis Ramirez	Brewers	-2%	-0.098
2014	Miguel Montero	Diamondbacks	-2%	-0.025
2014	Melky Cabrera	Blue Jays	-3%	-0.007
2014	Daniel Murphy	Mets	-3%	-0.015
2014	Martin Prado	- - -	-3%	-0.004
2014	Jacoby Ellsbury	Yankees	-3%	0.02
2014	Leonys Martin	Rangers	-3%	-0.035
2014	Carlos Gomez	Brewers	-3%	-0.029
2014	Buster Posey	Giants	-3%	0.023
2014	Alex Gordon	Royals	-4%	0.009
2014	Brandon Moss	Athletics	-4%	-0.063
2014	Victor Martinez	Tigers	-4%	0.101
2014	Nick Markakis	Orioles	-4%	0.026
2014	Kyle Seager	Mariners	-4%	0.02
2014	Billy Butler	Royals	-4%	-0.017
2014	Michael Brantley	Indians	-4%	0.066
2014	Brian Dozier	Twins	-4%	0.004
2014	Starlin Castro	Cubs	-5%	0.044
2014	Salvador Perez	Royals	-6%	0.003
2014	Alejandro De Aza	- - -	-7%	-0.008

What might make one more pessimistic about the players at the top of the list above, at least as far as the decline of their ISO goes, is that the players that saw the largest increase in FB% from 2012-2013 (chart below) generally continued on a downward trend in 2014. Out of the top 30 players that had the largest increase in FB% in 2013, 21 of those 30 saw a decrease in their ISO in 2013, and 15 out of the 21 continued to see a diminished ISO in 2014 (the bar graph illustrates this visually).

Name	FB% 12-13 (DIFF)	ISO 12-13 (DIFF)	ISO 13-14 (DIFF)
Alfonso Soriano	7%	-0.003	-0.088
Andre Ethier	6%	-0.025	-0.031
Marco Scutaro	6%	-0.026	-0.072
Adam Lind	5%	0.021	-0.05
Starlin Castro	5%	-0.045	0.044
Carlos Gomez	5%	0.12	-0.029
Chris Davis	4%	0.117	-0.139
Mitch Moreland	4%	0.051	-0.104
Adam LaRoche	4%	-0.072	0.03
Buster Posey	4%	-0.057	0.023
Michael Bourn	3%	-0.02	0.007
Brandon Phillips	3%	-0.013	-0.029
Chris Johnson	3%	-0.034	-0.038
Carlos Beltran	3%	-0.032	-0.026
Nate McLouth	3%	-0.038	-0.076
Martin Prado	3%	-0.001	-0.004
Joey Votto	3%	-0.036	-0.031
Matt Holliday	3%	-0.012	-0.021
Nick Markakis	3%	-0.037	0.026
Robinson Cano	2%	-0.036	-0.063
Daniel Murphy	2%	0.017	-0.015
Ian Desmond	2%	-0.045	0.002
Justin Upton	2%	0.051	0.02
Eric Hosmer	2%	0.019	-0.019
Darwin Barney	2%	-0.004	0.005
Troy Tulowitzki	2%	-0.013	0.034
Adrian Beltre	2%	-0.047	-0.025
Denard Span	2%	-0.01	0.013
Jon Jay	2%	-0.032	-0.02
Allen Craig	2%	-0.073	-0.042
Justin Morneau	2%	-0.02	0.025
Mike Moustakas	2%	-0.04	0.018
Nori Aoki	2%	-0.06	-0.009
Yoenis Cespedes	2%	-0.012	-0.012
Nick Swisher	1%	-0.024	-0.055
Marlon Byrd	1%	0.084	-0.039
Adrian Gonzalez	1%	0.004	0.038
Carlos Santana	1%	0.019	0.009
Ryan Zimmerman	1%	-0.006	-0.022
David Freese	1%	-0.055	0.004
Prince Fielder	1%	-0.037	-0.065
Edwin Encarnacion	1%	-0.015	0.017
Neil Walker	1%	0.021	0.028
Billy Butler	1%	-0.073	-0.017
Jay Bruce	1%	-0.047	-0.06
Jose Bautista	1%	-0.067	0
Alex Rios	1%	-0.058	-0.036
Zack Cozart	1%	-0.026	-0.048
Alexei Ramirez	1%	-0.003	0.039
Hunter Pence	1%	0.028	-0.032
Asdrubal Cabrera	1%	0.006	-0.013
Austin Jackson	0%	-0.034	-0.055
Paul Konerko	0%	-0.077	0
Alejandro De Aza	0%	0.012	-0.008
Erick Aybar	0%	-0.015	-0.011
Josh Hamilton	0%	-0.11	-0.031
Jose Altuve	0%	-0.029	0.032
Giancarlo Stanton	0%	-0.044	0.036
A.J. Pierzynski	0%	-0.07	-0.067
Pedro Alvarez	0%	0.017	-0.067
Mike Napoli	0%	-0.007	-0.052
Paul Goldschmidt	0%	0.045	-0.008
Shane Victorino	0%	0.029	-0.043
Alberto Callaspo	0%	0.001	-0.043
Ian Kinsler	0%	-0.03	0.009
Shin-Soo Choo	0%	0.019	-0.046
Mark Trumbo	0%	-0.003	-0.039
Michael Brantley	-1%	-0.002	0.066
Miguel Cabrera	-1%	0.011	-0.077
Victor Martinez	-1%	-0.012	0.101
Howie Kendrick	-1%	0.029	-0.038
Michael Cuddyer	-1%	0.022	0.049
Chase Utley	-1%	0.022	-0.053
Jimmy Rollins	-1%	-0.08	0.054
Chase Headley	-1%	-0.062	-0.02
Elvis Andrus	-1%	-0.032	0.009
Jacoby Ellsbury	-1%	-0.102	0.02
Jayson Werth	-1%	0.057	-0.051
Pablo Sandoval	-1%	-0.001	-0.003
Mark Reynolds	-1%	-0.035	0.025
Yadier Molina	-1%	-0.028	-0.054
J.J. Hardy	-1%	0.019	-0.066
Kendrys Morales	-1%	-0.023	-0.051
Ryan Doumit	-1%	-0.038	-0.027
Justin Smoak	-1%	0.027	-0.037
David Ortiz	-1%	0.009	0
Jason Kipnis	-1%	0.046	-0.078
Alcides Escobar	-2%	-0.032	0.026
Ben Zobrist	-2%	-0.075	-0.004
Dan Uggla	-2%	0.019	-0.119
Brett Gardner	-2%	0.033	0.023
Torii Hunter	-2%	0.023	-0.002
Andrew McCutchen	-2%	-0.036	0.038
Adam Dunn	-2%	-0.04	-0.027
Dustin Pedroia	-2%	-0.046	-0.016
Ichiro Suzuki	-3%	-0.026	-0.025
Adam Jones	-3%	-0.01	-0.02
Russell Martin	-3%	0.072	-0.011
James Loney	-3%	0.003	-0.041
Desmond Jennings	-3%	0.018	-0.027
Freddie Freeman	-3%	-0.015	-0.008
Coco Crisp	-4%	0.025	-0.066
Kyle Seager	-4%	0.003	0.02
Joe Mauer	-4%	0.026	-0.058
Alex Gordon	-4%	-0.004	0.009
Mike Trout	-4%	-0.004	0.04
Matt Wieters	-4%	-0.004	0.01
Evan Longoria	-5%	-0.021	-0.079
Yunel Escobar	-5%	0.019	-0.028
Gregor Blanco	-5%	0.026	0.031

Work needs to be done to see how long it takes for hitter FB% to stabilize, and once it does, we’ll be able to see how long we should wait before we should worry about a player’s deflated power potential.

Feature Image Courtesy of Jim Leuenberger