All-Star Games and Inter-League Play

Inter-league play started in 1997. Table 1 below shows the wins and losses for the AL year by year along with AL runs scored and NL runs scored. I found this data using the Split Finder at Stathead (part of Baseball Reference). Click here to go to that search.

Table 1

Year	AL W	AL L	AL W-L%	AL R	NL R
1997	97	117	0.453	994	1007
1998	114	110	0.509	1089	1078
1999	116	135	0.462	1246	1374
2000	136	115	0.542	1278	1233
2001	132	120	0.524	1175	1175
2002	123	129	0.488	1127	1097
2003	115	137	0.456	1239	1267
2004	127	125	0.504	1252	1210
2005	136	116	0.540	1230	1056
2006	154	98	0.611	1336	1115
2007	137	115	0.544	1352	1172
2008	149	103	0.591	1249	1014
2009	138	114	0.548	1206	1061
2010	134	118	0.532	1168	1098
2011	131	121	0.520	1074	993
2012	142	110	0.563	1142	1034
2013	154	146	0.513	1286	1197
2014	163	137	0.543	1298	1189
2015	167	133	0.557	1398	1169
2016	165	135	0.550	1427	1313
2017	160	140	0.533	1452	1346
2018	142	158	0.473	1254	1330
2019	134	166	0.447	1338	1497
2020	149	149	0.500	1378	1420
2021	167	133	0.557	1383	1346
2022	152	148	0.507	1329	1285
Totals	3634	3328	0.522	32,700	31,076

Using runs scored (AL R) and runs allowed (NL R), the AL's Pythagorean winning pct is .525, very close to the actual .522.

Table 2 has the results of the All-Star games since 1997. 

Table 2

Year	Winner	AL R	NL R
1997	A.L.	3	1
1998	A.L.	13	8
1999	A.L.	4	1
2000	A.L.	6	3
2001	Tie	4	1
2002	A.L.	7	7
2003	A.L.	7	6
2004	A.L.	9	4
2005	A.L.	7	5
2006	A.L.	3	2
2007	A.L.	5	4
2008	A.L.	4	3
2009	A.L.	4	3
2010	N.L.	1	3
2011	N.L.	1	5
2012	N.L.	0	8
2013	A.L.	3	0
2014	A.L.	5	3
2015	A.L.	6	3
2016	A.L.	4	2
2017	A.L.	2	1
2018	A.L.	8	6
2019	A.L.	4	3
2021	A.L.	5	2
2022	A.L.	3	2
	Totals	118	86

There were 25 games (no game in 2020 due to Covid). There was a tie in 2002. In the remaining 24 games, the AL has a 21-3 record for a .875 winning pct. That is far above the .522 pct it has in inter-league games. So it is possible that the leagues can be fairly even during a long period when one dominates the All-Star game.

The AL's Pythagorean pct for the All-Star games is .653. Not as dominant as .875, but still much higher than the .525 for regular season inter-league games. See All-Star Game History and Leaders from Baseball Reference.