By Byung Joon Yoon
This time, I will write about Kwanghyun-Kim, who was negotiating a contract with San Diego Padres after being posted for 2 million dollars. Now, while his contract negotiation failed, let’s have a brief look at what may have come about if he had played in the MLB. Taking data from pitchers who moved from Korea to Japan(or vise versa), and Japan to US. We will then compare that to Ryu’s performance to reach a conclusion. Now, let’s examine players who played in both Korea and Japan, pitched over 50 innings each country, and after 1990. Note that this after 1990 constraint was set up to reflect fairer evaluation of KBO, because I believe performance of players who came from Japan to Korea right after KBO started in 1982 will not help us predicting performance of a pitcher who pitched 30 years later. Their respective statistics are as follows:
As you see, ERA, K/BB, OAVG are all quite closely related. So, building a regression line:
JPN.era = 1.3148+0.7077*KOR.era
JPN.kbb = -0.4561+1.1543*KOR.kbb
JPN.oavg = 0.11445+0.66285*KOR.oavg
Est. performance of Kwanghyun Kim in JPN: ERA: 3.65 with K/BB: 1.55, Oavg: 0.315
It is to be noted though, there has been some health issues regarding him that affected his performance from 2011-2013, so if we can assume that he is healthy (which it looks like he is, from what we’ve seen in 2014), this statistic may be underestimating his true capability. Also, because his main issue was partial facial paralysis from stroke, it can indicate that he probably won't suffer from overworking his arm and shoulders, as many others does, and he is still 26. Unfortunately, with the contract negotiation deadline passed, it may be another season before we see how accurate my predictions are. Next time, I will return with estimated changes in performance for players that moved from Japan to US.