Korea's World Baseball Classic schedule:

Opponent	Time
Taiwan	Thursday, March 2, 6:30 PM PST
China	Friday, March 3, 6:00 PM PST
Japan	Sunday, March 5, 1:00 AM PST

Like the World Cup, the top 2 teams in Pool A advance to the next round, so Korea will probably need to win 2 of these 3 games to advance to the 2nd round. There they would play in another pool consisting of the top 2 teams from Pool B (USA, Canada, Mexico, and South Africa).

Baseball Prospectus ran simulations of Pool A and came up with the following probabilities:

Team	Pool A Winner	Pool A Runner-Up	Advance to Round 2
Japan	50.5%	31.5%	82.0%
Korea	33.6%	37.8%	71.4%
Taiwan	14.8%	26.1%	41.0%
China	1.2%	4.6%	5.7%

But while BP thinks Korea is better than Taiwan, the Vegas oddsmakers disagree:

Team	Pool A Winner
Japan	64.0%
Taiwan	19.9%
Korea	14.9%
China	1.2%

The consensus appears that Japan is the favorite and China is a huge underdog. This means that Thursday night's Korea vs Taiwan matchup has huge implications on who advances to Round 2. The winner will be well on their way, while the loser probably needs to upset Japan in order to have a chance to move on.