Pitching in his second season for the Samsung Lions in 2020, right-hander Won Tae-in was a much different pitcher in the second half than the first half -- and not in a good way.

He was 5-2 with a 3.56 ERA in his first 13 appearances, including one relief appearance, and he seemed to be on his way to a breakout campaign that many had expected from the then 20-year-old.

Then things fell apart over his final 14 starts, over which Won was just 1-8 with an ugly 6.15 ERA.

This year, Won is off to an even better start than in 2020. He leads the Korea Baseball Organization (KBO) with five wins and a 1.18 ERA. He won the Player of the Month for April on Monday in a landslide. Among other categories, Won is first among all players in wins above replacement (WAR) with 2.36. No pitcher allows fewer base runners than Won, whose walks and hits per innings pitched (WHIP) is a tidy 0.95.

Given Won's recent history, it's fair to wonder if he can sustain this level of pitching. Perhaps his ERA won't stay that low the whole season, but for now, Won likes what he sees whenever he looks up his own numbers.

"I find it incredible myself how well I've pitched this year," Won said Monday. "In fact, I check my stats every day."

In that dismal second half of 2020, Won lost his final eight decisions in a row. There were some hard-luck outings along the way -- getting no-decisions after six shutout innings on Sept. 22 and seven innings of one-run ball on Oct. 21 -- but for the most part, he got knocked around.

Another surprising aspect of Won's second-half swoon is that he was allowed to pitch so regularly at all. Manager Huh Sam-young could have demoted Won to the minor league and shielded him from the onslaught. Instead, with the Lions fading from contention down the stretch and having little left to play for, the skipper kept sending Won out every five or six days, hoping he'd get his act together.

Now, Won is grateful for that opportunity.

"I want to thank him for keeping me in the rotation, and that experience from last year has helped me a great deal this season," Won said, adding that he was able to overcome some wobbly early moments in his most recent start, last Friday against the Lotte Giants, because he leaned on what he went through in 2020.

Both Won and his catcher, Kang Min-ho, point to an improved slider as the key to the pitcher's early success.

"Up until last year, Tae-in mostly threw fastballs and changeups, but the slider has been really good this year," Kang said. "Hitters now have to respect that slider, and that makes the changeup even more effective."

Won said he did throw sliders in the past but not with the same amount of confidence that he has in that pitch today.

Last year, he threw it 20 percent of the time, up from 18 percent in 2019. This year, the usage rate has reached 24 percent.

The strong start to the season has allowed Won to dream big. He is on the provisional national team roster for the upcoming Tokyo Olympics, and manager Kim Kyung-moon recently singled out Won as a young pitcher to watch in the leadup to the Olympics.

"I was so honored, but at the same time, I began to worry that I shouldn't let him down," Won said. "For every athlete, competing at the Olympics is the ultimate. I'd like to put on the national team jersey."

Won's father, former infielder Won Min-goo, was also drafted by the Lions in 1984, but he never played pro ball. His son is already doing something his old man never did, and now the junior Won wants to take it a step further.

Behind Won's exceptional pitching, the Lions have jumped to first place through the weekend, at 19-12. There's still a lot of baseball left to play, as the Lions try to end their franchise-worst postseason drought at five years.

"We'd all love to host a postseason game at our stadium this year," Won said of Daegu Samsung Lions Park, which opened in 2016, the first year of their current drought. "I've been working hard all year to make sure I won't be fatigued in the second half." (Yonhap)