lowest era in world series history by a starter and a minimum of 3 gp

Madison Bumgarner has the best career ERA by a starting pitcher in the World Series when pitching in 3+ games, with an ERA of 0.29.

	NAME	ERA	G	SERIES	W	L	W%	GS	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Madison Bumgarner M. Bumgarner	0.29	4	World Series	4	0	1.000	4	27	1	1	0	31.0	12	1	1	1	5	2	0	0	107	0	7.84	1.45	5.40	0.29	25.2	4.7	0.55	.153	0.29	3.48
2	Jack Billingham J. Billingham	0.48	3	World Series	1	0	1.000	3	16	0	0	0	18.2	11	1	3	0	6	1	0	1	73	0	7.71	2.89	2.67	0.00	21.9	8.2	0.91	.220	1.45	5.30
3	Walker Buehler W. Buehler	0.50	3	World Series	2	0	1.000	3	22	0	0	0	18.0	7	1	1	0	3	0	0	0	61	0	11.00	1.50	7.33	0.00	36.1	4.9	0.56	.194	0.50	3.50
4	Harry Brecheen H. Brecheen	0.67	3	World Series	3	0	1.000	3	14	3	1	0	27.0	20	2	2	0	9	0	0	1	103	0	4.67	3.00	1.56	0.00	13.6	8.7	1.07	.250	0.67	6.67
5	Claude Osteen C. Osteen	0.86	3	World Series	1	2	.333	3	7	1	1	0	21.0	12	2	3	2	6	0	0	0	77	0	3.00	2.57	1.17	0.86	9.1	7.8	0.86	.161	1.29	5.14
6	Babe Ruth B. Ruth	0.87	3	World Series	3	0	1.000	3	8	2	1	0	31.0	19	3	3	1	10	1	0	0	116	1	2.32	2.90	0.80	0.29	6.9	8.6	0.94	.188	0.87	5.52
7	Sherry Smith S. Smith	0.89	3	World Series	1	2	.333	3	5	3	0	0	30.1	17	3	4	0	9	0	0	1	110	0	1.48	2.67	0.56	0.00	4.5	8.2	0.86	.177	1.19	5.04
8	Christy Mathewson C. Mathewson	0.97	11	World Series	5	5	.500	11	48	10	4	0	101.2	75	11	22	1	10	1	0	3	391	1	4.25	0.89	4.80	0.09	12.3	2.6	0.84	.224	1.95	6.64
9	Sandy Koufax S. Koufax	0.98	7	World Series	4	3	.571	7	60	4	2	0	55.0	36	6	10	2	11	0	0	1	207	0	9.82	1.80	5.45	0.33	29.0	5.3	0.85	.254	1.64	5.89
10	Hippo Vaughn H. Vaughn	1.00	3	World Series	1	2	.333	3	17	3	1	0	27.0	17	3	3	0	5	1	0	1	97	0	5.67	1.67	3.40	0.00	17.5	5.2	0.81	.230	1.00	5.67
11	Monte Pearson M. Pearson	1.01	4	World Series	4	0	1.000	4	28	3	1	0	35.2	19	4	5	1	7	0	0	0	133	0	7.07	1.77	4.00	0.25	21.1	5.3	0.73	.186	1.26	4.79
12	Josh Beckett J. Beckett	1.16	3	World Series	2	1	.667	3	28	1	1	0	23.1	14	3	3	0	6	1	0	0	88	0	10.80	2.31	4.67	0.00	31.8	6.8	0.86	.264	1.16	5.40
13	Spud Chandler S. Chandler	1.16	4	World Series	2	2	.500	4	15	2	1	0	31.0	24	4	6	0	6	0	0	0	119	0	4.35	1.74	2.50	0.00	12.6	5.0	0.97	.245	1.74	6.97
14	Eddie Plank E. Plank	1.17	6	World Series	2	4	.333	6	32	6	0	0	54.0	36	7	10	0	11	4	0	1	211	1	5.33	1.83	2.91	0.00	15.2	5.2	0.87	.220	1.67	6.00
15	Bill Hallahan B. Hallahan	1.21	5	World Series	3	1	.750	5	26	3	2	0	37.1	27	5	5	0	20	1	0	1	160	1	6.27	4.82	1.30	0.00	16.3	12.5	1.26	.239	1.21	6.51
16	Babe Adams B. Adams	1.33	3	World Series	3	0	1.000	3	11	3	1	0	27.0	18	4	5	2	6	1	0	0	106	0	3.67	2.00	1.83	0.67	10.4	5.7	0.89	.186	1.67	6.00
17	George Mullin G. Mullin	1.38	6	World Series	3	3	.500	6	35	6	1	0	52.0	40	8	16	1	12	3	0	0	207	0	6.06	2.08	2.92	0.17	16.9	5.8	1.00	.250	2.77	6.92
18	Orval Overall O. Overall	1.38	5	World Series	3	1	.750	5	27	3	1	0	39.0	27	6	8	0	11	0	0	0	152	1	6.23	2.54	2.45	0.00	17.8	7.2	0.97	.237	1.85	6.23
19	Jim Bouton J. Bouton	1.48	3	World Series	2	1	.667	3	11	1	0	0	24.1	19	4	5	0	10	0	0	1	100	2	4.07	3.70	1.10	0.00	11.0	10.0	1.19	.241	1.85	7.03
20	Ron Darling R. Darling	1.53	3	World Series	1	1	.500	3	12	0	0	0	17.2	13	3	4	2	10	1	0	1	75	2	6.11	5.09	1.20	1.02	16.0	13.3	1.30	.220	2.04	6.62
21	George Earnshaw G. Earnshaw	1.58	8	World Series	4	3	.571	8	56	5	1	0	62.2	39	11	14	2	17	0	0	1	245	1	8.04	2.44	3.29	0.29	22.9	6.9	0.89	.218	2.01	5.60
22	Jon Lester J. Lester	1.65	5	World Series	4	1	.800	5	30	0	0	0	32.2	22	6	6	3	7	1	0	0	124	0	8.27	1.93	4.29	0.83	24.2	5.6	0.89	.229	1.65	6.06
23	Mickey Lolich M. Lolich	1.67	3	World Series	3	0	1.000	3	21	3	0	0	27.0	20	5	5	2	6	1	0	0	104	0	7.00	2.00	3.50	0.67	20.2	5.8	0.96	.243	1.67	6.67
24	Ron Guidry R. Guidry	1.69	4	World Series	3	1	.750	4	26	2	0	0	32.0	20	6	6	4	14	0	0	0	125	0	7.31	3.94	1.86	1.13	20.8	11.2	1.06	.198	1.69	5.63
25	Stan Coveleski S. Coveleski	1.74	5	World Series	3	2	.600	5	11	4	1	0	41.1	31	8	9	2	7	0	0	0	162	0	2.40	1.52	1.57	0.44	6.8	4.3	0.92	.204	1.96	6.75