Can one player lead both conferences in one season?

The Major Baseball League (MBL) has pretty easy standards for qualifying for leading in an average category.

For batters: 502 plate appearances (PA), even for batting average (BA), which does not use PA as its denominator.  Go figure.

For pitchers: 162 innings.

Jimmy Rollins set the record for PA in 2007: 778.  Only 28 times have batters had at least 750 PA.

For a batter to qualify for BA leadership in each conference in the same season the batter would need at least 502 PA times 2: 1,004.  That's very unlikely.

However, it is possible for a pitcher to qualify.  Many pitchers in modern times have had 162*2 = 324 innings in a season.  Since WWII (for the twitter intelligentsia, that's World War II (2): "since" would be after 1945) it's been done 27 times.  For instance, Sandy Koufax had 335 innings pitched (IP) in 1965 and 323 in 1966, just one short.

Rk	Player	IP	Year	Age	Tm	Lg	G	GS	CG	SHO	GF	W	L	W-L%	SV	H	R	ER	BB	SO	ERA	ERA+	HR	BF	HBP
1	Wilbur Wood	376.2	1972	30	CHW	AL	49	49	20	8	0	24	17	.585	0	325	119	105	74	193	2.51	126	28	1490	7
2	Mickey Lolich	376.0	1971	30	DET	AL	45	45	29	4	0	25	14	.641	0	336	133	122	92	308	2.92	124	36	1538	7
3	Bob Feller	371.1	1946	27	CLE	AL	48	42	36	10	5	26	15	.634	4	277	101	90	153	348	2.18	151	11	1512	3
4	Wilbur Wood	359.1	1973	31	CHW	AL	49	48	21	4	1	24	20	.545	0	381	166	138	91	199	3.46	116	25	1531	7
5	Robin Roberts	346.2	1953	26	PHI	NL	44	41	33	5	2	23	16	.590	2	324	119	106	61	198	2.75	153	30	1412	2
6	Steve Carlton	346.1	1972	27	PHI	NL	41	41	30	8	0	27	10	.730	0	257	84	76	87	310	1.97	182	17	1351	1
7	Gaylord Perry	344.0	1973	34	CLE	AL	41	41	29	7	0	19	19	.500	0	315	143	129	115	238	3.38	117	34	1410	5
8	Gaylord Perry	342.2	1972	33	CLE	AL	41	40	29	5	1	24	16	.600	1	253	79	73	82	234	1.92	168	17	1345	12
9	Phil Niekro	342.0	1979	40	ATL	NL	44	44	23	1	0	21	20	.512	0	311	160	129	113	208	3.39	119	41	1436	11
10	Robin Roberts	336.2	1954	27	PHI	NL	45	38	29	4	6	23	15	.605	4	289	116	111	56	185	2.97	136	35	1331	5
11	Denny McLain	336.0	1968	24	DET	AL	41	41	28	6	0	31	6	.838	0	241	86	73	63	280	1.96	154	31	1288	6
12	Sandy Koufax	335.2	1965	29	LAD	NL	43	41	27	8	2	26	8	.765	2	216	90	76	71	382	2.04	160	26	1297	5
13	Phil Niekro	334.1	1978	39	ATL	NL	44	42	22	4	1	19	18	.514	1	295	129	107	102	248	2.88	142	16	1389	13
14	Wilbur Wood	334.0	1971	29	CHW	AL	44	42	22	7	2	22	13	.629	1	272	95	71	62	210	1.91	189	21	1316	7
15	Nolan Ryan	332.2	1974	27	CAL	AL	42	41	26	3	1	22	16	.579	0	221	127	107	202	367	2.89	118	18	1392	9
16	Phil Niekro	330.1	1977	38	ATL	NL	44	43	20	2	1	16	20	.444	0	315	166	148	164	262	4.03	111	26	1428	8
17	Robin Roberts	330.0	1952	25	PHI	NL	39	37	30	3	2	28	7	.800	2	292	104	95	45	148	2.59	141	22	1310	5
18	Gaylord Perry	328.2	1970	31	SFG	NL	41	41	23	5	0	23	13	.639	0	292	138	117	84	214	3.20	125	27	1336	8
19	Fergie Jenkins	328.1	1974	31	TEX	AL	41	41	29	6	0	25	12	.676	0	286	117	103	45	225	2.82	126	27	1305	8
20	Catfish Hunter	328.0	1975	29	NYY	AL	39	39	30	7	0	23	14	.622	0	248	107	94	83	177	2.58	144	25	1294	5
21	Mickey Lolich	327.1	1972	31	DET	AL	41	41	23	4	0	22	14	.611	0	282	100	91	74	250	2.50	127	29	1321	11
22	Nolan Ryan	326.0	1973	26	CAL	AL	41	39	26	4	2	21	16	.568	1	238	113	104	162	383	2.87	123	18	1355	7
23	Juan Marichal	325.2	1968	30	SFG	NL	38	38	30	5	0	26	9	.743	0	295	106	88	46	218	2.43	123	21	1307	6
24	Gaylord Perry	325.1	1969	30	SFG	NL	40	39	26	3	1	19	14	.576	0	290	115	90	91	233	2.49	142	23	1345	11
25	Bert Blyleven	325.0	1973	22	MIN	AL	40	40	25	9	0	20	17	.541	0	296	109	91	67	258	2.52	156	16	1321	9
Rk	Player	IP	Year	Age	Tm	Lg	G	GS	CG	SHO	GF	W	L	W-L%	SV	H	R	ER	BB	SO	ERA	ERA+	HR	BF	HBP
26	Fergie Jenkins	325.0	1971	28	CHC	NL	39	39	30	3	0	24	13	.649	0	304	114	100	37	263	2.77	141	29	1299	5
27	Denny McLain	325.0	1969	25	DET	AL	42	41	23	9	0	24	9	.727	0	288	105	101	67	181	2.80	134	25	1304	4

Provided by Baseball-Reference.com: View Play Index Tool Used
Generated 7/3/2012.