In the words of their own manager, the Doosan Bears have beat themselves with sloppy play to fall behind the Nexen Heroes two games to none in their Korea Baseball Organization (KBO) first-round playoff series.

The Heroes walked off on the Bears twice to take a commanding 2-0 lead in the best-of-five series. They can eliminate the Bears with a win in Game 3 Friday at the Bears' home, Jamsil Stadium.

While the finishes of the two games were surely dramatic -- the first was won on a ninth-inning single, and a 10th-inning hit ended the second -- both games, especially Game 2 on Wednesday, had some embarrassing moments for both sides.

Concerning the Bears, who made the fewest errors in the league during the regular season and feature some of the KBO's fastest and smartest runners, it was especially surprising that they found themselves on the wrong end on base paths and on defense.

On Wednesday, a throwing error by Doosan pitcher Oh Hyun-taek set up the game-winning hit by Kim Ji-soo.

Park Byung-ho, who has good speed for his 185-centimeter, 97-kilogram frame with 30 steals in the last two seasons, was on first base after getting hit by a pitch. With one out, the Heroes' bench put him in motion for a hit-and-run play.

He took off from first base as Kim fouled off a couple of pitches. Park appeared to have gotten into Oh's head, as the pitcher kept throwing to first to check the runner. Then Kim Hyun-soo, a natural left fielder playing first base in this series, mishandled a throw from Oh and the ball skipped into foul territory.

Park rounded second and headed for third. Kim promptly delivered the walk-off single.

In the eighth inning alone, Doosan's reliever Hong Sang-sam threw three wild pitches, two of which directly led to a Nexen run that tied the game at 1-1. With Park at the plate, and a runner on second, catcher Yang Eui-ji got up from behind the plate to signal an intentional walk for the slugger.

Hong inexplicably threw the ball over Yang's head, as Seo Geon-chang, a speedy runner on second, easily moved to third. Then on the very next pitch, Hong threw one in the dirt and had the ball bounce off the chest of Yang. Seo, who had stutter-stepped halfway toward home plate, sprinted home to even the score.

After Wednesday's game, Doosan's manager Kim Jin-wook didn't mince words.

"We tried our best but we made mistakes that should never have been made late in the game," Kim said dejectedly. "We really beat ourselves today."

The Bears also had two runners thrown out at second when they tried to stretch an infield single. In the top seventh, Jeong Su-bin, who had 27 steals during the regular season, laid down a bunt along the first baseline. When Andy Van Hekken's throw to first went wild and into right field, Jeong got on his way to second. Right fielder Yoo Han-joon, though, nailed the speedy runner with a perfect throw.

In the top of the 10th, Oh Jae-won, third in the KBO with 33 steals, got an infield single to short when Kang Jung-ho's throw sailed over the first baseman Park Byung-ho's head. Oh did not hesitate as he ran toward second, but the ball caromed off the front wall of the dugout and right back to Park, who threw out Oh by several meters.

Jeong Su-bin had been one of the few bright spots in the Doosan lineup, having gone 5-for-6 in the first two games, but he'd also made two baserunning gaffes in Game 1. He got caught in a rundown between third and home after an apparent squeeze bunt attempt in the second inning. In the seventh, Jeong was doubled up on first when he failed to make it back on a line drive to center field.

"Jeong Su-bin has been great at the plate, but I had to talk to him about his baserunning from the first game," Kim Jin-wook said.

"He went out and made another mistake today."

The manager observed that his players might have been pressing too much, after losing the first game in the bottom of the ninth inning.

"We made the fewest errors during the regular season, but I think pressure really affected our play a great deal," Kim said. "I think we need to be more collected and composed. We're going to concentrate on that during our offday."

At least Jeong Su-bin and Co. reached base and were trying to make something happen. The same couldn't be said about the heart of the Bears' order.

Their 3-4-5 hitters, Min Byeong-heon, Kim Hyun-soo and Hong Sung-heun, have gone 2-for-20 with five strikeouts and one walk.

Kim and Hong were first and second on the club in homers with 16 and 15, respectively. Min batted a career-best .319 in the regular season, and he and Hong were tied for second on the team with 21 doubles apiece.

Manager Kim decided to play the ailing Kim Hyun-soo at first for the series to take some defensive pressure off his team. Kim Hyun-soo, who was visibly limping prior to Game 1 favoring his right ankle, hasn't been forced to make difficult plays at first, but he also hasn't been his productive self at the plate.

The manager hinted at a possible change in the lineup for Game 3.

"I think Hyun-soo's problems are really psychological," Kim Jin-wook said. "Guys in the middle of our lineup are slumping. I will make some changes if necessary."

Since the first-round KBO playoff series change from best-of-three to best-of-five in 2008, only one team has been able to overcome a 2-0 series deficit to reach the next round. The 2010 Doosan Bears lost the first two games against the Lotte Giants, and won the next three by a combined score of 28-13. (Yonhap News)