The Curious Case of Jae Seo

Last year, Jae Seo had a fine first full season with the New York Mets. He compiled a 9-12 mark in 31 starts for a team with the second-worst record in the league, and sported a 3.82 ERA. For a ballclub with an aging rotation, Seo offered some hope for Mets fans, who envisioned young arms like Aaron Heilman, Matt Peterson and Scott Kazmir teaming with Seo in their rotation of the future.

This year, Seo went to spring training thinking he had earned the number four spot in the rotation. Unfortunately, he gave up 30 hits in 21 innings for a 7.48 ERA, which is not what the Mets were hoping to see. So he was sent back to the minors and 36-year-old Scott Erickson was given his rotation slot. Just one week later, Seo was recalled when Erickson strained a hamstring, and Seo will probably get at least one start to prove he belongs in the show, after all.

This is not the first time that Seo has overcome an obstacle to get to the major leagues. In fact, his personal history is an ode to overcoming obstacles.

The Mets signed Seo out of Korea in 1997. At the time, they were investing a lot of energy into scouting and signing Asian players, partly inspired by Bobby Valentine’s knowledge of Japanese players. That this Asian shopping spree only snagged Seo, Masato Yoshii and Tsuyoshi Shinjo is a story for another day.

The Seo signing received a moderate amount of publicity. The Mets thought they had signed a fine young arm, and didn’t hesitate to say so. He started out very well, with a 2.27 ERA in eight Florida State League starts. He had a 92 mph fastball, good secondary pitches and outstanding control (38 strikeouts and 10 walks in 36 innings), and Baseball America ranked him the Mets’ fourth-best prospect during the offseason.

Unfortunately, Seo began to feel twinges in his elbow and the Mets decided to rest him for the remainder of 1998. They wanted to treat his fine young arm carefully. You can’t blame them for being cautious.

In 1999, Seo managed to avoid military service (which is mandatory in Korea) by pitching for the national team in the World Championships (helping them finish second). Post-publication correction: Seo actually pitched in the Asian Games held in Thailand in 1998 (Korea won the gold medal). However, the pain in his elbow persisted, and he finally had major elbow surgery after pitching only 14 innings (albeit with a 1.90 ERA) in the Florida State League in 1999.

Athletes do it all the time, but recovering from major surgery is difficult and painful. Seo spent the rest of 1999 and all of 2000 in rehab, soft-tossing and probably wondering if he would ever pitch without pain again. He dropped off the prospect lists, and his future as a major leaguer was dubious, at best. During his first three years as a Mets’ prospect, he had pitched only 50 innings.

But Jae Seo is evidently an intrepid young man, and he finally returned to the St. Lucie pitching mound in 2001, nearly two years since last leaving it. He had lost several miles off his fastball, now registering between 86 and 88 miles per hour, but he continued to maintain outstanding control and those secondary pitches, and he compiled a 3.55 ERA in six starts. Encouraged, the Mets promoted him to AA Binghamton, where he produced a 1.94 ERA in 10 starts, and AAA Norfolk, where he sported a 3.42 ERA in nine starts. Things were finally looking up.

Seo spent most of 2002 at AAA Norfolk. He managed to stay healthy all year and put together an okay season: a 4.00 ERA in 24 starts, with an 87/22 strikeout/walk ratio in 128 innings. He was maintaining his phenomenal control, but was barely breaking 90 with his fastball.

Two-thirds of the way through the season, there was a weird story about Seo not eating meals on days he pitched. I was reminded of a college friend of mine, who told me that he liked to skip meals on exam days, so he could go into the exam “hungry.” Evidently, Seo had the same idea.

The Mets sat him down, gave him a menu, and said “Jae, you must eat!” Lo and behold, he put together a number of good starts toward the end of the season, including one with the major league club. Seo went from fasting to a cup of coffee, and it must have tasted very sweet indeed, particularly after so many years of pain and doubt.

Seo impressed new manager Art Howe in spring training 2003, and Howe stuck him in the Mets’ rotation and left him there all year. He was fascinating to watch. He still didn’t have much on his fastball, neither speed nor movement. But he proved to be a master of speed control. His changeup was his out pitch, and it was a good one.

Pitchers like Seo can sometimes lose their effectiveness when they go around the league a second time. Hitters learn to track them, and the adjustment dance between batters and pitchers begins. That didn’t quite happen with Seo. For instance, he pitched twice against the Atlanta Braves, who in 2003 were one of the best hitting teams of all time. In the first game he held them to one run in seven innings, and in the second game, just a week later, he held them to two runs in eight innings.

He was a control/speed control pitcher and a pretty good one. A right-handed Jamie Moyer without grey hair, if you will.

In fact, here is a comparison of Seo’s and Moyer’s 2003 pitching stats per nine innings pitched:

A Hardball Times Update
Goodbye for now.
          SO9     BB9     HR9      H9    BABIP    GB/FB
Seo       5.3     2.2     0.9     9.2     .280     0.94
Moyer     5.4     2.8     0.8     8.3     .267     0.85

Like Moyer, Seo was a fly-ball, control pitcher who gave up about the average number of home runs. BABIP is batting average on batted balls that stay in the park, which is sometimes a function of fielding more than pitching. When the Mets signed Mike Cameron away from the Mariners, they put perhaps Moyer’s key defender behind Seo, which would theoretically make him that much more Moyerish.

However, there were some concerns running underneath Seo’s fine 2003 performance. For instance, he gave up 14 unearned runs, and his “runs allowed” average was actually 4.5 runs per game, which was just about league average. Sure, the Mets’ subpar fielding could be blamed, but I doubt that Seo was entirely blameless for those unearned runs. In comparison, no other Mets starter gave up more than four unearned runs.

Seo also had problems in July and August, as you can see in this table:

MONTH        ERA       RA     SO9     BB9     HR9    BABIP
April       3.18     4.80     4.4     0.3     0.6     .345
May         3.00     3.23     4.1     2.5     0.7     .227
June        3.12     3.46     5.8     2.1     0.0     .299
July        6.61     7.23     6.6     3.5     1.2     .332
August      5.34     5.34     4.5     2.0     1.7     .245
September   1.71     3.17     6.3     2.6     0.9     .235

ESPN called July and August a “dead arm” period for Seo, and this may be true. The good news is that he had his best month in September, giving the team hope for 2004.

Pitchers like Jae Seo walk a tightrope. They depend on their control and their smarts, so their learning curve is long. Jamie Moyer didn’t become “good” until his 30s, for instance. That makes it hard to project Jae Seo’s future. (Actually, it’s hard to project most pitchers’ futures, but hey, this is my story.)

On the one hand, the pitchers most similar to Seo at this stage, according to Baseball Reference, didn’t have much of a major league career. On the other hand, Baseball Prospectus’ PECOTA system says that the most similar pitcher to Seo has been John Burkett. Except for his 2001 career year, Burkett has been an average pitcher, maybe slightly below average.

At this time, I believe this is the most probable future for Jae Seo: an average or slightly-below average major league starter. Mets fans might think I’m being a bit harsh, but I seriously doubt he will match last year’s ERA. His fastball is a little too straight and his pitches lack movement in general.

On the other hand, there is absolutely nothing wrong with an average major league starter. The fourth and fifth spots in many a championship rotation have consisted of average starters, and Seo might still learn to throw pitches with a bit more movement, such as a two-seam fastball. I think Howe and Rick Peterson have been trying to get him to throw one, and that may have led to his spring training woes.

The Mets really need young pitchers like Seo and Tyler Yates to succeed, and they should find the patience to give them a full shot. When you’re not likely to contend, you don’t waste rotation spots on guys who are nine years older than your good young pitchers. You let the young guys learn. The Mets would be smart to keep Seo in the major league rotation, even if he takes a few lumps.

Jae Seo has had a lot of tough luck on the way to the majors, but he’s stuck it out. I have a feeling he’ll succeed this year as well. Root for the guy.

References & Resources
Seo’s story was told with the help of my back issues of Braunstein’s Met and Yankee Minor League Reporter. Thanks to Hyoung-joo Lee for the correction regarding the 1998 Asian Games.

Moyer’s and Seo’s stats are courtesy of

Dave Studeman was called a "national treasure" by Rob Neyer. Seriously. Follow his sporadic tweets @dastudes.

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