Still on the Board: Wei-Yin Chen

With the holiday break coming to an end, Phase II of the 2015-16 free agent and trade markets is about to kick off in earnest. As noted by August Fagerstrom earlier today, player movement is likely to be heavier than in the typical January, with plenty of top free agents, particularly on the position player side, still on the market.

The first wave of free-agent signings was particularly kind to starting pitchers, both at the top and middle of the market. Still, a handful of starters — Wei-Yin Chen, Yovani Gallardo and Ian Kennedy at the forefront — remain available. Does the market have enough suitors and dollars to satisfy those three? Today, we’ll look at the first of those three, who has spent all of his stateside career with the Orioles.

Wei-Yin Chen is one of many former stars of the Japanese League to make his way to the U.S. major leagues in recent years, though he arrived with far less fanfare than the most visible imports, Yu Darvish and Masahiro Tanaka. Chen was not subject to the posting process that those two — and, most recently, Kenta MaedaDavid Price, Zack Greinke or Johnny Cueto, and he lacked the long-term track record of Jordan Zimmermann or the raw stuff and athleticism of Jeff Samardzija. He figured to slot in right behind those guys, however, alongside John Lackey, Hisashi Iwakuma and Scott Kazmir, and probably ahead of Mike Leake.

Here we stand, however, with the younger Leake the recipient of the best deal by far among Chen’s peer group, with the lefty still standing on the sidelines. How good is Wei-Yin Chen, and what sort of offer might he deserve at this point? Even more importantly, given the current market conditions, what type of deal might he realistically expect, and from whom might he receive it?

Let’s utilize plate appearance outcome frequency and production by ball-in-play (BIP) type data, adjusted for BIP authority allowed, to get a better feel. First, the frequency data:

Plate Appearance Outcome Frequencies: Wei-Yin Chen, 2015

Metric	%	REL	PCT
K	19.3%	97	48
BB	5.2%	71	12
POP	5.5%	153	89
FLY	33.9%	109	75
LD	20.1%	96	34
GB	40.5%	92	27

This paints a pretty clear picture of Chen’s profile. First and foremost, he’s an extreme strike-thrower, as evidenced by his low BB rate, which ranked in the 12th percentile among qualifying MLB hurlers last season. Talk about consistency: Chen’s BB rate ranked in that exact same 12th percentile in 2014 as well. He’s not merely a pitch-to-contact soft-tosser, either; his K rate is quite respectable, ranking in the 48th percentile in 2015. This matches his career-best mark, set in his 2012 rookie campaign.

Chen is clearly a fly-ball pitcher. He gets plenty of free outs via the pop up, ranking in the 89th percentile in that category last season. This marked a career best, though it was the third time in four seasons that he posted a pop up percentile rank of 80 or higher. His fly ball rate percentile rank of 75 is squarely in line with career norms; his career average fly ball percentile rank in four MLB seasons is 72.5.

Most BIP type frequencies correlate quite well from year to year, with the exception of liner rates, which fluctuate quite wildly. Chen’s low 2015 liner rate percentile rank of 34 needs to be eyed with some skepticism. In the previous two seasons, Chen’s liner rate percentile ranks allowed were 94 and 65. Was Chen’s 2015 improvement in this area real progress, or simply random variation? This is something to watch moving forward.

So we have a lefty who throws strikes, uses guile and finesse to get his share of swings and misses and strikeouts, and pads his free out total with pop ups. There are lots of fly balls, and in most seasons, plenty of liners that run the risk of turning into real damage. To assess his overall risk level, we’ll need to measure the authority of those flies and liners, and that’s where the production by BIP type data will help:

Relative Production by BIP Type: Chen, 2015

Metric	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	FIP	TRU ERA
FLY	0.232		0.680	157	131
LD	0.695		1.244	130	100
FLY + LD	0.469		0.969	124	98
GB	0.238		0.275	90	102
ALL BIP	0.325		0.565	113	100
ALL PA	0.259	0.297	0.449	102	91	3.34	4.04	4.16	3.58

The actual production allowed on each BIP type is indicated in the batting average (AVG) and slugging (SLG) columns, and is converted to run values and compared to MLB average in the REL PRD (or Unadjusted Contact Score) column. That figure is then adjusted for context, such as home park, team defense, luck, etc., in the ADJ PRD (or Adjusted Contact Score) column. For the purposes of this exercise, sacrifice hits (SH) and flies (SF) are included as outs and hit by pitchers (HBP) are excluded from the on-base percentage (OBP) calculation. One quick note here: I have presented this type of analysis many times, but only recently have I begun to show fly ball and line drive line items both separately and combined.

It is immediately apparent that Chen allowed quite a bit of damage relative to the league on fly balls and liner drives. His unadjusted fly ball and liner Contact Scores were 157 and 130, separately, and 124 when combined. Once adjusted for BIP authority, however, they drop to 131 and 100 separately, and 98 combined. Chen was one of the unluckiest qualifying MLB starters on such batted balls. Adjusted for authority, Chen also yielded average grounder production, with a 102 Adjusted Contact Score.

Add them all together, and Chen yielded a .325 OBP and .565 SLG on all BIP in 2015, for a 113 Unadjusted Contact Score. Adjusted for authority, however, and he’s exactly average at 100. Add back the Ks and BBs, and Chen’s “tru” ERA is 3.58, not as good as his actual ERA of 3.34, but way better than his FIP of 4.16. His FIP doesn’t credit him for his high pop-up rate, and it hammers him for his low grounder total. He’s not “screwed” by the FIP calculation as much as, say, Marco Estrada, but he’s treated unfairly nonetheless.

In 2014, Chen’s Adjusted Contact Score on all BIP was quite a bit higher, at 115, with the material differences being a much higher liner rate allowed, and harder ground ball authority. On balance, I would consider 2014 to be the outlier, and Chen to be an average to very slightly below-average contact manager moving forward, with his tendency to allow high liner rates my main concern.

At this point, let me re-introduce the concept of the K/BB Contact Score Multiplier. Basically, based on a pitcher’s K and BB rates relative to the league, a multiplier is assigned and applied to a pitcher’s Contact Score to estimate his “tru”, or true-talent ERA. In 2015, Chen’s K rate was in the league-average range (within one-half standard deviation in either direction), and his BB rate was over one full STD lower than league average. Based on results going back to 2009, Chen’s multiplier is 94.6. That’s pretty good, and there are no signs of near-term attrition; average-K, low-BB guys can last awhile.

If Chen is a league average, or slightly below league average contact manager, let’s be conservative and give him a 105, or 5% below league average Contact Score, which, combined with a 94.6 multiplier give him almost exactly a league average ERA (99.3). Using this same method for other free-agent starters, this slots Chen ahead of Leake and very close to Kazmir. Kazmir owns the upside, Chen the floor. For me, Leake was a clear overpay, and Kazmir a fair deal. Even in this belated market phase, I still believe that Chen will find a deal similar in length and size to Kazmir’s.

Who’s going to give it to him? Well, the Dodgers would seem to have already signed the number of southpaws they need. Many potential suitors have shopped elsewhere, or are now likely to move on to position player targets. The one glaring exception would appear to be the Orioles, Chen’s only U.S. employer to date. He’s waged the wars of the AL East successfully, the club has the money to spend and the positional need, and knows the player very well. Once the Chris Davis situation plays itself out, I expect Chen to be next on their list.

Teams with large stadium dimensions should also check in on Chen should he become available at a bargain rate. Even more specifically, clubs playing in stadiums that hinder high fly balls more than low flies/line drives — Arizona, Atlanta, Baltimore, Cleveland, Detroit, Kansas City, Los Angeles (AL), Miami, Oakland, Pittsburgh, St. Louis, San Francisco, Seattle, Tampa Bay, Texas, and Washington — should at least pay a courtesy call. Chen allows more high fly balls than his peers; this is especially deadly in Boston, Cincinnati, Colorado, Houston, Milwaukee, New York (AL), and San Diego, to name a few parks.

Going forward, I see Chen as a somewhat lesser version of Hiroki Kuroda. Their success levels in Japan were similar, as are their K/BB profiles. Kuroda was a somewhat superior contact manager; he pulled off the odd Daily Double of inducing both grounders and pop-ups, which I believe is beyond Chen’s skill level. If Chen is a 100-105 contact manager, Kuroda was a 90-95. Chen isn’t likely to reach Kuroda’s peak, or last quite as long, but still projects as a reliable #3-4 starter throughout the next few seasons.