Here is scenario in which KIA wins 13 additional games (74 total) but does not reach the postseason.

Here are the final standings in the scenario:
            Team	W	L	D	PCT	GB
          Hanwha	81	60	3	0.5745	0.0
              LG	80	61	3	0.5674	1.0
              KT	75	65	4	0.5357	5.5
             SSG	75	65	4	0.5357	5.5
         Samsung	76	66	2	0.5352	5.5
             KIA	74	65	5	0.5324	6.0
           Lotte	67	70	7	0.4891	12.0
              NC	64	74	6	0.4638	15.5
          Doosan	60	78	6	0.4348	19.5
          Kiwoom	46	94	4	0.3286	34.5

To construct the scenario, we start with the current standings:
            Team	W	L	D	GL	PCT	GB
              LG	80	49	3	12	0.620	0.0
          Hanwha	76	53	3	12	0.589	4.0
             SSG	65	60	4	15	0.520	13.0
              KT	65	63	4	12	0.508	14.5
         Samsung	66	64	2	12	0.508	14.5
           Lotte	63	64	6	11	0.496	16.0
              NC	61	62	6	15	0.496	16.0
             KIA	61	65	4	14	0.484	17.5
          Doosan	56	70	6	12	0.444	22.5
          Kiwoom	43	86	4	11	0.333	37.0

The next two tables show, respectively, how many of their remaining games each team wins and ties against each of the other teams in the scenario:

					Scenario Additional Wins Against
Team	Doosan	Hanwha	KIA	Kiwoom	KT	LG	Lotte	NC	Samsung	SSG	Wins
Doosan	-	1	0	1	0	1	0	1	0	0	4
Hanwha	0	-	0	1	0	3	1	0	0	0	5
KIA	0	3	-	1	1	0	0	4	2	2	13
Kiwoom	2	0	0	-	0	0	1	0	0	0	3
KT	0	2	0	1	-	4	0	1	0	2	10
LG	0	0	0	0	0	-	0	0	0	0	0
Lotte	1	0	0	0	0	1	-	2	0	0	4
NC	0	0	0	1	0	2	0	-	0	0	3
Samsung	1	0	0	2	1	1	3	1	-	1	10
SSG	4	1	0	1	0	0	1	3	0	-	10
-----------------------------------------------------------------------------------
Losses	8	7	0	8	2	12	6	12	2	5

					Scenario Additional Draws (Ties) With
Team	Doosan	Hanwha	KIA	Kiwoom	KT	LG	Lotte	NC	Samsung	SSG	Total
Doosan	-	1	0	0	0	0	1	2	0	0	0
Hanwha	0	-	0	0	0	1	0	0	0	0	0
KIA	0	0	-	2	0	0	1	0	0	1	1
Kiwoom	0	0	0	-	0	0	0	1	0	1	0
KT	0	0	0	0	-	0	0	1	0	0	0
LG	0	0	0	0	0	-	2	0	0	0	0
Lotte	0	0	1	0	0	0	-	0	1	0	1
NC	0	0	0	0	0	0	0	-	0	1	0
Samsung	0	0	0	0	0	0	0	0	-	1	0
SSG	0	0	0	0	0	0	0	0	0	-	0
-----------------------------------------------------------------------------------
Total	0	0	1	0	0	0	1	0	0	0

The next two tables show, respectively, how many total games each team wins and ties against each of the other teams in the scenario:

					Scenario Total Wins Against
Team	Doosan	Hanwha	KIA	Kiwoom	KT	LG	Lotte	NC	Samsung	SSG	Wins
Doosan	-	9	6	10	4	7	7	6	6	5	60
Hanwha	6	-	9	14	9	8	10	9	8	8	81
KIA	9	7	-	8	9	5	8	10	9	9	74
Kiwoom	6	2	6	-	5	7	5	5	4	6	46
KT	11	7	7	11	-	8	6	7	10	8	75
LG	9	7	11	9	8	-	9	8	9	10	80
Lotte	8	6	7	11	8	5	-	9	7	6	67
NC	8	6	6	10	8	8	7	-	7	4	64
Samsung	10	8	7	12	6	7	8	9	-	9	76
SSG	11	8	6	9	8	6	10	11	6	-	75
-----------------------------------------------------------------------------------
Losses	78	60	65	94	65	61	70	74	66	65

					Scenario Total Draws (Ties) With
Team	Doosan	Hanwha	KIA	Kiwoom	KT	LG	Lotte	NC	Samsung	SSG	Total
Doosan	-	1	1	0	1	0	1	2	0	0	6
Hanwha	0	-	0	0	0	1	0	1	0	0	3
KIA	0	0	-	2	0	0	1	0	0	1	5
Kiwoom	0	0	0	-	0	0	0	1	0	1	4
KT	0	0	0	0	-	0	2	1	0	0	4
LG	0	0	0	0	0	-	2	0	0	0	3
Lotte	0	0	1	0	0	0	-	0	1	0	7
NC	0	0	0	0	0	0	0	-	0	1	6
Samsung	0	0	0	0	0	0	0	0	-	1	2
SSG	0	0	0	0	0	0	0	0	0	-	4
-----------------------------------------------------------------------------------
Total	6	3	5	4	4	3	7	6	2	4

KIA has clinched a postseason berth.
Here are the current standings:
            Team	W	L	D	GL	PCT	GB
              LG	80	49	3	12	0.620	0.0
          Hanwha	76	53	3	12	0.589	4.0
             SSG	65	60	4	15	0.520	13.0
              KT	65	63	4	12	0.508	14.5
         Samsung	66	64	2	12	0.508	14.5
           Lotte	63	64	6	11	0.496	16.0
              NC	61	62	6	15	0.496	16.0
             KIA	61	65	4	14	0.484	17.5
          Doosan	56	70	6	12	0.444	22.5
          Kiwoom	43	86	4	11	0.333	37.0

KIA's worst possible winning percentage is 0.4357  (61 wins, 79 losses, and 4 draws).
KIA will finish ahead the following teams:
1) Kiwoom: best possible winning percentage 0.3857  (54 wins, 86 losses, and 4 draws).