3. Home Run rates summary (AB/HR) leaders 1920-2019.

Third consecutive post on this. Please read the previous two posts in this series:
1. Top Home Run hitters rates per year. Saturday, November 30, 2019 8:59 AM
2. Home Run rates (AB/HR) leaders 1920-2019. Saturday, November 30, 2019 6:55 PM

AB: At Bats
HR: Home Runs
MLB: Major League Baseball: both American League and National League
Home Run Rate: AB/HR (lower is better)
N: number of MLB teams that season
Top home run hitters: N hitters with the most HR, plus any ties at the bottom
Home Run Rate MLB: for N hitters: total AB / total HR
Home Run Rate hitters: AB/HR
Dif: Home Run Rate hitter - Home Run Rate MLB
PctDif: Dif/Home Run Rate MLB
HR#: rank among N hitters for HR
PctDif#: rank among N hitters for PctDif

Hitters are ranked by relative position: 1, 2, 3, ... Ties would have the same number and then rank number would resume. For example, if four players are tied at third place: 1, 2, 3, 3, 3, 3, 7, 8, ...

The data covers 100 seasons. Including ties 112 batters led MLB in home runs in those 100 seasons. 57 of 112 HR leaders also led in PctDif: 50.9%. HR# is the rank in homers:

HR#	CountOfHR#
1	57
2	16
3	6
4	6
5	6
6	1
7	1
11	1
12	1
14	1
16	1
22	1
25	1
26	1

52 batters led in the 100 seasons, 32 only once. Here are the 20 who led more than once. PctDif in decimal, not percentage form. Max and Min are for the data in this study. Sorted by Num, YearMin:

First	Last	Num	PctDifMax	PctDifMin	HRmax	HRmin	YearMin	YearMax
Babe	Ruth	10	0.7633968	0.3809697	60	35	1920	1931
Mark	McGwire	7	0.4916667	0.2706873	70	39	1987	1999
Ralph	Kiner	6	0.4572729	0.2308102	54	37	1947	1952
Barry	Bonds	5	0.5251974	0.3024919	73	45	2000	2004
Jimmie	Foxx	4	0.4998518	0.2894046	58	35	1932	1939
Ted	Williams	4	0.4378258	0.2956722	38	29	1941	1960
Harmon	Killebrew	3	0.3579831	0.2529002	48	44	1962	1967
Hank	Aaron	3	0.453768	0.2934275	47	34	1971	1973
Dave	Kingman	3	0.4243013	0.2908016	48	36	1975	1979
Mike	Schmidt	3	0.4281405	0.2782008	48	31	1980	1983
Lou	Gehrig	2	0.4093823	0.3671998	49	49	1934	1936
Hank	Greenberg	2	0.4831471	0.4404072	58	44	1938	1946
Eddie	Mathews	2	0.237386	0.2064765	47	46	1953	1959
Willie	Mays	2	0.3960323	0.2711725	52	51	1955	1965
Mickey	Mantle	2	0.3321692	0.3281957	54	52	1956	1961
Ryan	Howard	2	0.3054743	0.2237282	58	48	2006	2008
Carlos	Pena	2	0.357975	0.2414281	46	39	2007	2009
Jose	Bautista	2	0.3976934	0.2855389	54	43	2010	2011
Giancarlo	Stanton	2	0.3524755	0.2699047	37	27	2012	2015

Ken Phelps 2    36.48%    35.47%    24   24    1984  1988 (discovered late; only 290 and 297 AB; HR#: 26 and 23)

All three for Hank Aaron were late in his career. All five for Barry Bonds were comparably late. Both did it consecutive seasons.

Ted Williams is a surprise, leading four times, including in his final season: 1960. We don't tend to think of Williams as a home run hitter because his season high was only 43 but much of that was due to all the walks he received.

500 home run hitters who led only once:
Frank Robinson 586
Reggie Jackson 563
Willie McCovey 521

But some 500 home run hitters never led in PctDif:
Alex Rodriguez 696
Albert Pujols 656
Ken Griffey 630
Jim Thome 612
Sammy Sosa 609
Rafael Palmeiro 569
Manny Ramirez 555
David Ortiz 541
Frank Thomas 521
Ernie Banks 512
Gary Sheffield 509
Eddie Murray 504

Mark McGwire led for two teams (As, Cardinals) and no team, splitting 1997 between them. J.D. Martinez led in 2017 playing for two teams: Tigers and Diamondbacks. Both McGwire and Martinez split "leagues": AL/NL. McGwire led MLB in home runs in 1997 but neither "league". Jimmie Foxx led for As and Red Sox in separate years.

26 of the current 30 franchises had a batter lead in PctDif at least once but not San Diego, Kansas City Royals, Colorado, Arizona:

franchID	Num	BatFirst	BatLast	PctDifMax	PctDifMin	HRmax	HRmin	YearMin	YearMax
NYY	15	Ruth	Mantle	0.7633968	0.3281957	60	31	1920	1961
SFG	10	Ott	Bonds	0.5251974	0.2711725	73	26	1944	2004
OAK	8	Foxx	McGwire	0.4998518	0.2654692	58	36	1932	1996
ATL	7	Nieman	Jones	0.453768	0.2064765	51	14	1945	2005
PIT	7	Kiner	Stargell	0.4572729	0.2308102	54	28	1947	1978
DET	5	York	Fielder	0.4831471	0.2885075	58	35	1937	1990
BOS	5	Foxx	Williams	0.4378258	0.2894046	38	29	1939	1960
PHI	5	Schmidt	Howard	0.4281405	0.2237282	58	31	1980	2008
STL	4	Hornsby	McGwire	0.4916667	0.2943726	70	39	1925	1999
BAL	4	Powell	Trumbo	0.3764828	0.1852019	53	39	1964	2016
MIN	3	Killebrew	Killebrew	0.3579831	0.2529002	48	44	1962	1967
NYM	3	Kingman	Strawberry	0.4243013	0.2853259	39	36	1975	1988
CHC	2	Wilson	Kingman	0.3871429	0.3354631	56	48	1930	1979
CIN	2	Kluszewski	Foster	0.3033921	0.2749796	52	49	1954	1977
TEX	2	Howard	Gonzalez	0.2784379	0.2688682	46	44	1968	1993
ANA	2	Jackson	Trout	0.2502971	0.246442	45	39	1982	2019
HOU	2	Bagwell	Carter	0.2961682	0.2896032	39	37	1994	2014
TBD	2	Pena	Pena	0.357975	0.2414281	46	39	2007	2009
TOR	2	Bautista	Bautista	0.3976934	0.2855389	54	43	2010	2011
FLA	2	Stanton	Stanton	0.3524755	0.2699047	37	27	2012	2015
CLE	1	Colavito	Colavito	0.274132	0.274132	41	41	1958	1958
WSN	1	Bailey	Bailey	0.2099009	0.2099009	28	28	1970	1970
CHW	1	Allen	Allen	0.327114	0.327114	32	32	1974	1974
SEA	2	Phelps	Phelps	36.48%	35.47%	24	24	1984	1988
MIL	1	Deer	Deer	0.2321639	0.2321639	33	33	1986	1986
LAD	1	Muncy	Muncy	0.2939046	0.2939046	35	35	2018	2018
	0	McGwire	Martinez	0.3815468	0.353331	58	45	1997	2017