Home Run Proficiency: Bonds, Aaron, Ruth, Mays.

Starting to look at batters with at least 493 home runs (HR).

Rk	Player	HR	From	To	Age	G	PA	AB	R	H	2B	3B	RBI	BB	IBB	SO	HBP	SH	SF	GDP	SB	CS	BA	OBP	SLG	OPS	Pos	Tm
1	Barry Bonds	762	1986	2007	21-42	2986	12606	9847	2227	2935	601	77	1996	2558	688	1539	106	4	91	165	514	141	.298	.444	.607	1.051	*78/D9	PIT-SFG
2	Hank Aaron	755	1954	1976	20-42	3298	13941	12364	2174	3771	624	98	2297	1402	293	1383	32	21	121	328	240	73	.305	.374	.555	.928	*9783D/45	MLN-ATL-MIL
3	Babe Ruth	714	1914	1935	19-40	2503	10620	8399	2174	2873	506	136	2213	2062		1330	43	113		2	123	117	.342	.474	.690	1.164	971/83	BOS-NYY-BSN
4	Willie Mays	660	1951	1973	20-42	2992	12496	10881	2062	3283	523	140	1903	1464	192	1526	44	13	91	251	338	103	.302	.384	.557	.941	*8/39675	NYG-SFG-TOT-NYM

Provided by Baseball-Reference.com: View Play Index Tool Used
Generated 1/14/2013.

Sunday, January 6, 2013
Home Run Proficiency Career

In a future post I'll take the percentage difference per season from their career number for the top career HR hitters to look for trends such as improvement late in a career and will create graphs.
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This is the first swipe.  Click this link to view Home Run Proficiency data for each season for batters with at least 493 career home runs (HR).  There are four tabs with that data.  Then there are two tabs with data and graphs for the four batters with the most career HR listed above.  Their data is aligned by age, figured simply as season year minus birth year, not using June 30 as a mid season break point as baseball-reference.com does.  So some ages might not line up as they do in that website.  For instance Bonds was born July 24, 1964, Aaron February 5, 1934.  baseball-reference.com shows Bonds a year younger than I do.

So far I have graphs for the big four with their Home Run Proficiency v. the league, which have been labeling x and now also that data v. each of their individual career Home Run Proficiency numbers previously labeled y.

1. I have no means to apply a HR ball park factor, so that should be considered when evaluating this data.

2. I did not remove each season's data from the batter's career, which would have provided more accuracy but added yet another layer and I needed to wrap it up.  It probably skews Ruth's data the most but he's so far removed from the others in every measurement that it probably doesn't matter that much.

If I ever figure out how to copy Google Docs spreadsheet data into its blogger creation software then I can show some of it more neatly then currently.  So view the data using the link mentioned above.  Here is a sloppy form:

Age Bonds Aaron Mays Ruth
20 -97.03% -45.83% 30.18%
21 -69.81% -69.62% -31.55%
22 -63.07% -70.92% -48.57%
23 -64.24% 2.00% 20.14% 60.19%
24 -28.70% -51.20% 32.43% 37.19%
25 -68.04% -20.03% -21.89% 85.92%
26 -2.31% 10.85% -19.02% 28.22%
27 -31.34% -37.97% -50.72% -18.80%
28 53.39% 20.39% -20.44% -8.97%
29 32.58% 36.03% -33.36% 19.16%
30 33.81% -42.50% 0.82% -38.91%
31 -25.36% -14.89% 39.19% 19.79%
32 2.18% 22.01% 28.96% 42.70%
33 -6.73% 42.27% 87.91% 11.78%
34 -27.29% 23.14% 102.13% -23.49%
35 7.11% 63.67% 15.93% -30.85%
36 11.36% 19.32% -14.36% -23.34%
37 99.43% 123.83% 26.22% -38.93%
38 58.41% 57.76% -70.24% -43.16%
39 53.04% 110.20% -11.06% -63.62%
40 52.30% 26.83% -28.28% -42.50%
41 67.04% -90.66% -64.90%
42 -33.26% -28.40% -85.02%
43 -5.25%

Age Bonds Aaron Mays Ruth

Career 1.8391 1.6363 1.5016 7.8412
Bonds Aaron Mays Ruth

Aaron started playing in Atlanta at age 32.  Bonds and Aaron at age 37 both have their highest Home Run Proficiency v. their own careers.  Ruth and Mays decline as one would expect.  Aaron has his second highest at age 39, Bonds at age 41.  Mays age 34, Ruth age 25.

What made Bonds and Aaron so different?  In future posts I'll compare them against their contemporaries.  Bonds v. others in the steroid era.  Aaron v. the 500 HR hitters of the 1950s and 1960s.