In the domestic equivalent of the "Subway Series," two Seoul-based clubs will go toe-to-toe in the opening round of the South Korean professional baseball playoffs starting on Tuesday.

The Nexen Heroes will host the Doosan Bears to start the best-of-five first round of the Korea Baseball Organization (KBO) playoff series at Mokdong Stadium in western Seoul at 6 p.m. on Tuesday. It will be the first-ever postseason clash between the two clubs.

The Heroes, who finished third in the regular season, will host the first two games. The No. 4 seed Bears will be at home for Game 3 and, if necessary, Game 4 at Jamsil Stadium in southern Seoul starting on Friday.

The Heroes hold the edge in their regular season meetings at 9-7, and six of those wins came in Mokdong.

The winner of this series will go on to face the LG Twins in the best-of-five second round. The Twins earned the bye after finishing second in the regular season.

The Samsung Lions, who captured the pennant, are waiting in the championship Korean Series.

Throughout the postseason, all weekday games will start at 6 p.m., while games on weekends and holidays will begin at 2 p.m.

This series, evenly matched on paper, features two of the league's most potent offenses. The Bears led the KBO with 699 runs scored and a .289 average, while the Heroes hit the most home runs with 125.

The Bears' lineup features a handful of smart, opportunistic hitters with extra-base power. Kim Hyun-soo led the club with 16 homers, 90 RBIs and 23 doubles, while batting .343 with runners in scoring position.

The Heroes are led by perhaps the KBO's most feared slugger, first baseman Park Byung-ho. The reigning league MVP is almost certain to pick up his second straight MVP, after leading the league with 37 home runs, 117 RBIs, 91 runs scored, 92 walks and a .602 slugging percentage.

If the Bears pitch around Park, they will still have to contend with power-hitting shortstop Kang Jung-ho, who enjoyed his second straight 20-homer season and drove in a career-high 96 runs, and emerging third baseman Kim Min-sung, who broke out with 15 homers and 72 RBIs, along with 24 doubles.

While Nexen boasts more power, Doosan is the speedier club. The Bears led the KBO with 172 steals, 41 more than the Heroes, and had four players with at least 20 swipes, led by Oh Jae-won with 33.

Both clubs had mediocre pitching during the regular season, with their team ERAs ranked in the lower half of the league. They also ranked in the middle of the pack in runs allowed.

For the Heroes, Brandon Knight and Andy Van Hekken tied for the team-lead with 12 wins. Closer Son Seung-lak recorded 46 saves, one shy of tying the KBO record held by Oh Seung-hwan of the Lions.

Dustin Nippert led the Bears with 12 wins, even though he missed a large chunk of the season with an upper back injury.

Left-hander Yu Hui-kwan went a surprising 10-7 with a 3.53 ERA, often fooling hitters with a slow curve that travels around 75 kilometers per hour.

The bullpen could be the Bears' weak link. They don't have the go-to closer like the Heroes' Son, forcing manager Kim Jin-wook to take a "closer-by-committee" approach with limited success.

On defense, the Bears committed the fewest errors with 61. Lee Jong-wook and Jung Soo-bin, two of the KBO's fastest players, cover plenty of ground in center and right field on defense.

In contrast, the Heroes made 97 errors, second most in the KBO, though they still have solid defensive players in second baseman Seo Geon-chang, shortstop Kang and center fielder Lee Taek-geun.

One-time pitching prospect Jang Ki-young has a cannon for an arm in left field. (Yonhap News)