Is Barry Bonds really the home run king?
Barry Bonds is seemingly cruising to and past Hank Aaron’s home run record. At the start of the season there was some doubt as to whether he would achieve the magic number in 2007, but a slew of long balls in April and May ensured that he will (barring catastrophic injury). In fact, with the way he is swinging the bat there is a fair chance that Bonds will continue playing in 2008 and possibly, heaven forbid, beyond (watch out Julio Franco).
However, it might all have been so different. And no, I’m not talking about the steroids fug, but rather about whether Bonds would still be aiming for the same high-water mark or one that was more lofty set by Ken Griffey Jr.
Let’s investigate some more.
The early days of Junior’s career
Junior has had a career of two halves, roughly defined by his switching teams from the Mariners to the Reds in 2000. Take a look at his stats since he burst on the scene in 1989, his rookie year (that’s not a typo—he has been in this business for 19 years):
Year Ag Tm G AB HR HR/AB 1989 19 SEA 127 455 16 3.5% 1990 20 SEA 155 597 22 3.7% 1991 21 SEA 154 548 22 4.0% 1992 22 SEA 142 565 27 4.8% 1993 23 SEA 156 582 45 7.7% 1994 24 SEA 111 433 40 9.2% 1995 25 SEA 72 260 17 6.5% 1996 26 SEA 140 545 49 9.0% 1997 27 SEA 157 608 56 9.2% 1998 28 SEA 161 633 56 8.8% 1999 29 SEA 160 606 48 7.9% 2000 30 CIN 145 520 40 7.7% 2001 31 CIN 111 364 22 6.0% 2002 32 CIN 70 197 8 4.1% 2003 33 CIN 53 166 13 7.8% 2004 34 CIN 83 300 20 6.7% 2005 35 CIN 128 491 35 7.1% 2006 36 CIN 109 428 27 6.3% 2007 37 CIN 83 294 23 7.8%
Back in his formative years his home run rate climbed from 4% to a peak of around 9% as he started to slam 50 fence-hoppers a season. By the time he had left the Mariners to move to the Midwest he had already amassed 398 home runs and seemed destined for an assault on Hank Aaron’s mark of 755. All that was required of him was to stay healthy and motivated. (Note: At that point Bonds had ratcheted up 445 homers although he had been playing for three years longer—like for like over the same time period Bonds recorded 380 longballs.)
Griffey and Cincinnati
Unfortunately, as all know, Griffey’s career in Cincinnati has been anything but healthy. In Seattle he racked up seven seasons where he played in at least 150 games (it may have been more were it not for the 1994 strike). He is currently in his eighth season in Ohio and only in one year, his first, has he come even remotely close to that total.
Every season between 2001 and 2006 the DL seemed to be Griffey’s second home. In total he hit the doctor’s surgery an eye-watering eight times in those six years, missing a total of 274 games—we’re not just talking about a sniffle here; that is some serious time out. For the sadists among you here is the gruesome run-down:
2001: Once, hamstring tear 2002: Twice, torn knee tendon and that darn hamstring again 2003: Twice, dislocated shoulder and torn ankle tendon 2004: Twice, yup, those hamstrings again (x2) 2005: None,but had a foot injury when on the 40-man roster (so wasn't on DL) 2006: Once,inflamed biceps tendon (right knee)
Unbelievably he also broke his wrist in the 2006 offseason wrestling with his kids but managed to recover in time to start mashing the ball again in 2007—you couldn’t make this stuff up.
It isn’t only injury that may have prevented Junior from notching some gaudy home run numbers later in his career. Fans and the media have also questioned his motivation while wearing the stripes of Cincinnati. First there was the hullabaloo over his jersey number. He initially wanted number 24, which he wore in Seattle, but it was already retired in honor of Tony Perez. That meant he had to settle for number 30, his Pop’s old number, but he sure kicked up a helluva stink in the process.
Further there were suggestions that Griffey was too focused on exploring other non-baseball commercial opportunities and did not pay enough attention to his fitness in his late 20s, which may have prevented some of his more serious injuries. For instance, in the late ’90s and early ’00s he appeared in a number of baseball games, an episode of the Simpsons, The Fresh Prince of Bel Air, and baseball movies Little Big League and Summer Catch. Another theory is that the turf of the Kingdome wreaked havoc on his legs in his later years.
All of this is incidental to the central question: Had he stayed healthy would he have established a new home run record?
The short answer and the long answer
Let’s start with the short answer so you can click on to the next article! Griffey has missed about 300 games due to injury since his time in Cincinnati. Doing the math on the games he did play he hit a home run a little over once every four games, on average. That equates to an additional 75 home runs, which moves his total to 660.
However, that also includes a couple of seasons where injury clearly took the edge off his performance (2002 and 2003, for instance). Normal seasons in those years may have yielded another 20 long balls boosting his total to about 680. That would put him about 80 shy of Aaron and Bonds—still some gap. He would need to play for another three to four years in order to snatch the record, which would by no means be a certainty; it also presupposes that Bonds will hang up his spikes sooner rather than later.
Okay, that quick and dirty exercise assumed that Griffey maintained his historic production, but perhaps injury hampered his assault on the record more than we think. Let’s turn our attention to the long answer and try to be marginally more scientific about the whole process. Given that he completed his tour in Seattle largely unharmed it isn’t too unreasonable to assume that he was following a fairly typical aging profile (as far as age curves are typical).
Here is a typical home run aging curve, courtesy of Tangotiger:
Age Home run factor* 21 0.68 22 0.78 23 0.88 24 0.91 25 0.95 26 0.98 27 1 28 0.99 29 0.98 30 0.96 31 0.95 32 0.92 33 0.87 34 0.86 35 0.8 36 0.76 37 0.71 * A value of 1 indicates peak age; all other numbers relative to this
This curve has been calculated using a match pairs process. This involves looking at players in consecutive years, comparing home run rates and weighting by the lowest PA in the two years. Rinse and repeat for every player above a certain plate appearance cut-off and you get the data above.
A value of 1.00 represents peak age, and for home runs that occurs at age 27. From that point on you can see that home run skill gradually drops off. If we apply the age curve backwards to the first part of Griffey’s career we see that between the age of 22 and 28 he hit 290 home runs against 350 predicted (assuming 150 games a season), though that includes a season out (parts of 1994 and 1995), which accounts for a lot of the gap.
Let’s apply Tango’s aging curve to Griffey after the age of 28 and see how many home runs he should have hit from the point he joined Cincinnati (again assuming 150 games a season). To get the baseline home run I’ve averaged his 26-28 years of home runs in Seattle and applied the aging curve from that point.
Age Actual HR Adjusted HR Age factor 29 48 53 0.98 30 40 52 0.96 31 22 52 0.95 32 8 50 0.92 33 13 47 0.87 34 20 47 0.86 35 35 44 0.8 36 27 41 0.76 Age 19-28 398 Age 29-36 333 This season 21 TOTAL 752
Wow! 752—although the assumptions are a tad aggressive perhaps (including his age 27 and 28 seasons gives him more than six 50-home run seasons)! Remember that this analysis does not include 2007, so if you add Junior’s 21 longballs this year then it is he and not Bonds who would have smashed the record. Add in the fact that Bonds is a few years older and there would be no debate as to who was the best slugger. Or would there be?
Bonds fights back
One thing that is worth noting is that Griffey has played most of career in hitter-friendly confines, whereas Bonds, for the last decade or so, has been fighting sea breezes blowing in from San Francisco Bay. We can partly adjust for this by applying a park factor. I have chosen Baseball Reference’s park factor for simplicity. This is a batter park factor rather than a home run park factor and won’t be pure (as Griffey’s and Bonds’ hitting are included in the calculation). Anyway, with those limitations in mind take a look at what the park factor does to the home run totals (note: the home runs are based on actual totals and not on the above age-adjusted numbers):
Ken Griffey Junior Barry Bonds
Year Team HR PF Adj. HR Year Team HR PF Adj. HR
1989 SEA 16 103 16 1986 PIT 16 102 16
1990 SEA 22 101 22 1987 PIT 25 101 25
1991 SEA 22 100 22 1988 PIT 24 99 24
1992 SEA 27 101 27 1989 PIT 19 97 20
1993 SEA 45 100 45 1990 PIT 33 96 34
1994 SEA 40 102 39 1991 PIT 25 98 26
1995 SEA 17 103 17 1992 PIT 34 99 34
1996 SEA 49 100 49 1993 SFG 46 96 48
1997 SEA 56 99 57 1994 SFG 37 95 39
1998 SEA 56 100 56 1995 SFG 33 96 34
1999 SEA 48 103 47 1996 SFG 42 96 44
2000 CIN 40 107 37 1997 SFG 40 98 41
2001 CIN 22 99 22 1998 SFG 37 96 39
2002 CIN 8 108 7 1999 SFG 34 89 38
2003 CIN 13 100 13 2000 SFG 49 91 54
2004 CIN 20 92 22 2001 SFG 73 91 80
2005 CIN 35 106 33 2002 SFG 46 91 51
2006 CIN 27 108 25 2003 SFG 45 99 45
2007 CIN 23 108 21 2004 SFG 45 103 44
2005 SFG 5 98 5
2006 SFG 26 100 26
2007 SFG 17 100 17
TOTAL 576 TOTAL 783
That chart illustrates just how good Bonds was and is. Not only has he hit over 750 home runs, but he has done it in a park that by all accounts is a pitcher’s haven (God bless Barry Zito). Based on the Baseball Reference calculation, Bonds’ park-adjusted home run figure is 783—he would have passed Aaron last year.
Final Thoughts
The home run record is all about one man at the moment: Barry Bonds, although Alex Rodriguez could enter the picture at some point in the future. However, had Junior remained healthy we could have been in the process of witnessing a historic two-horse race and the spectre of steroids would have made Griffey the firm fan’s favorite.
As it is Griffey will join the 600 club soon and will be an automatic Hall of Famer. A great career for sure, but at the turn of the century it promised to be perhaps the greatest ever.
References & Resources
Baseball Reference remains an invaluable source for all things baseball (and probably a lot of things non-baseball)!