Number of runs in the postseason

There were four postseason games today. Exciting! What made today more exciting was that all four games were close games. Three of them were one run games and one of them went to extra innings.

I decided to answer the following question I had from few months ago: Would the average of runs scored be different in playoff games? How about the difference of runs scored in those games?

I went to baseball-reference.com, and first searched for 2014 team runs.

Okay. So there were 19761 runs scored and if we divide that number by 30 * 162, we know that each team on average scored 4.066 runs per game in 2014. How about postseason so far? Including tonight's game, 87 runs in 8 games, so each team scored 5.438 runs on average.

Clearly I want to take more samples than just 8 games, so I took a look at past 20 years of postseason (633 games.) On average, each team scored 4.212 runs in the postseason. During that time period, each team scored 4.664 runs on average in the regular season. Lower!

I put down average runs for a team in a game (number of games) by year.

Year	Regular	Postseason	Year	Regular	Postseason
'14	4.07 (2430)	5.44 (8)	'04	4.81 (2428)	5.19 (34)
'13	4.17 (2431)	3.55 (38)	'03	4.73 (2430)	4.03 (38)
'12	4.32 (2430)	3.49 (37)	'02	4.62 (2426)	5.15 (34)
'11	4.28 (2429)	4.88 (38)	'01	4.78 (2429)	3.56 (35)
'10	4.38 (2430)	3.63 (32)	'00	5.14 (2429)	4.15 (31)
'09	4.61 (2430)	4.33 (30)	'99	5.08 (2428)	4.58 (31)
'08	4.65 (2428)	4.22 (32)	'98	4.79 (2432)	3.62 (30)
'07	4.80 (2431)	4.59 (28)	'97	4.77 (2266)	4.21 (34)
'06	4.86 (2429)	3.80 (30)	'96	5.04 (2267)	4.20 (32)
'05	4.59 (2431)	4.37 (30)	'95	4.85 (2017)	4.21 (34)

I colored the background for the years when teams scored more runs on average in the postseason. There were only four out of 20 as shown above.

Usually the number of runs varies significantly among teams and one can argue that playoff teams are with better offense, but they are also with better defense so number of runs does not increase in the postseason.

I believe the main reason is that in the postseason, aces get to start more often and No. 5 starters do not get much chance to pitch. I am interested to see the breakdown of number of runs scored against No. 1 starters, against No. 2 starters, and so on. I can't think of a nice way to write a query for that as of now. Maybe I can approximate it by looking at few particular teams and looking for the ratio between runs allowed by each pitcher.

Another reason I can think of is the bullpen usage. In the postseason, teams tend to use bullpen a bit differently, simply because they are playing as if there is no tomorrow. Andrew Miller who never pitched in the 6th inning since April 18th did pitch in the 6th inning against the heart of the lineup of Tigers in Game 1 for example. I didn't get to the difference of runs scored, but it would be very interesting to see (My guess is that the postseason games are tighter.)

Anyway, 10:9 game with Wainwright and Kershaw starting looks even more shocking, considering that the postseason games are with lower runs scored. Oh well, it's postseason and anything can happen in the postseason I guess.