What is a precursor for playoff success, win percentage is 1-run games or blowouts?

You hear over and over that a team's positive win percentage in 1-run games makes them more probable than not a playoff team. This is true.

However, a team's win percentage record in games decided by ± 5 runs is a much better gauge.

Why? It says a team can dominate offensively and can't be dominated as opposed to a one run game which can be decided by a fluke play.

Here are the World Series Champions and runner-ups from 2004-2015.

First is games decided by ± 5 runs. Ranks are determined by league, by win percentage. Champion in bold.

The AL average is 3.4, the NL average is 3.6.

YEAR	TEAM	AL	NL	TEAM
2015	KCR	3	9	NYM
2014	KCR	6	7	SFG
2013	BOS	1	2	STL
2012	DET	7	6	SFG
2011	TEX	3	2	STL
2010	TEX	3	4	SFG
2009	NYY	3	5	PHI
2008	TBR	4	2	PHI
2007	BOS	2	1	COL
2006	DET	2	3	STL
2005	CHW	6	2	HOU
2004	BOS	1	1	STL

Now let's look at how these same teams ranked in win percentage in 1-run games. Same criteria as above.

The AL average is 6.5, the NL average is 6.25.

YEAR	TEAM	AL	NL	TEAM
2015	KCR	1	8	NYM
2014	KCR	10	13	SFG
2013	BOS	7	4	STL
2012	DET	11	2	SFG
2011	TEX	14	5	STL
2010	TEX	4	4	SFG
2009	NYY	3	5	PHI
2008	TBR	1	6	PHI
2007	BOS	12	8	COL
2006	DET	5	11	STL
2005	CHW	1	5	HOU
2004	BOS	9	4	STL

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