KBO Magic (Tragic) Numbers

Rank / Team	PR	PS	PCT	PCT_max	PCT_min	Rank_max/min	G	G_rem	W	W_max	L	L_max	D
1 Kia Tigers	112 (117)	107 (121)	.700	.938	.146	1 / 10	30	114	21	135	9	123	0
2 NC Dinos	117 (112)	109 (118)	.633	.924	.132	1 / 10	30	114	19	133	11	125	0
3 Samsung Lions	117 (111)	110 (117)	.600	.916	.126	1 / 10	31	113	18	131	12	125	1
4 SSG Landers	118 (110)	111 (116)	.567	.909	.119	1 / 10	31	113	17	130	13	126	1
5 LG Twins	119 (108)	112 (114)	.533	.901	.113	1 / 10	32	112	16	128	14	126	2
6 Doosan Bears	121 (106)	114 (111)	.469	.882	.104	1 / 10	32	112	15	127	17	129	0
7 Kiwoom Heroes	123 (107)	116 (112)	.448	.889	.090	1 / 10	29	115	13	128	16	131	0
8 Hanwha Eagles	124 (105)	117 (110)	.400	.875	.083	1 / 10	30	114	12	126	18	132	0
9 KT Wiz	124 (103)	118 (107)	.355	.860	.077	1 / 10	32	112	11	123	20	132	1
10 Lotte Giants	127 (103)	121 (107)	.286	.860	.056	1 / 10	29	115	8	123	20	135	1

Magic and tragic (aka elimination) numbers are provided both for the pennant race (1st place) and postseason (5th place). For simplicity, this explainer will refer to the postseason numbers only (the competition for the #5 spot), but the others work the same way.
If a team's postseason magic number reaches zero, they are no longer in danger of being eliminated and are guaranteed a spot in the top 5. Conversely, if the team's postseason tragic (elimination) number reaches zero, they have been decisively eliminated and no longer have any chance of playing in the postseason.
A team's "magic number" decreases by one if the team wins, or if the next contending team loses. The "next contending team" is the team with the best chance of taking the 5th spot. This is typically the #6 team, but may not be, depending on how many draws and remaining games the other teams have.
If two teams in contention finish the regular season with an identical W-L-D record, they will play a tiebreaker game with no inning limit on the following day to determine the final standings. Their record against each other will determine where the game is played.
Note that the max/min rank numbers are calculated naively, based on best/worst case scenarios, where the best case scenario assumes that all other teams lose all of their remaining games. This is obviously impossible, but it is a necessary simplification for now, and in all but the closest contests, is accurate enough for our purposes.

#4 and #5 face off in a “best of 3 series” (Wild Card) in which the #4 team starts with a one win lead. In other words, either one or two games will be played: the #5 team must win two games to advance, whereas the #4 team can advance with just one win (or even a tie).
The winner of that series faces #3 in a best of 5 series (Semi-Playoff/준PO/준플레이오프).
The winner of that series faces #2 in a best of 5 series (Playoff/PO/프레이오프).
The winner of that series faces #1 in a best of 7 series known as the Korean Series (코시/한국시리즈).
A best of 5 series consists of two games at the higher-ranked team’s home, a travel day, two at the lower-ranked team’s home, another travel day, and the final game (if needed) at the higher-ranked team’s home.
The Korean Series schedule can vary, but typically consists of two games at the higher ranked team’s home, a travel day, three games at the lower-ranked team’s home, another travel day, and the final two games (if needed) at the higher ranked team’s home.