By Mike Dunn, GM of the Niihama-shi Ghosts
Sunday, July 24, 2011

If there's one thing that reading Bill James attending college statistics class taught me, it is not to trust perceptions.  Look at the numerical data that lie below the surface, I was taught to see if they conform to the perception.

So when my Head Trainer Kuniaki Suzuki handed me the latest Ghosts’ injury report, it could have fueled my perception that the Ghosts season has been the most injury-plagued of the entire league.  The report details two serious injuries -- stud middle reliever Yataro Kawaguchi had ruptured a tendon in his finger and is most likely done for the year, while RF Tokugawa Okamoto strained his medial collateral ligament and is out for six weeks.

Okamoto, in fact, was the fourth regular Ghosts outfielder to suffer a serious injury in a span of just one month.  Since June 28 ^th, Tatsuchiki Suzuki, Sadakuno Ishikawa and Tameyoshi Watanabe had gone down with injuries of 3, 5 and 4 weeks, respectively.  All this on the heels of the season's start, in which three regulars went down in the span of three days.

So from my vantage point, the Injury Gods were dumping big time on the Ghosts, who have nonetheless managed to stay in contention in the Shining Star Group.  My first inclination was to again go whining to reporters and others, "Wa wa wa, my team keeps getting hurt."  Fans will call into the talk shows to bemoan the fates.

But was this perception true?  Perhaps my view was skewed; perhaps other General Managers and coaches were also looking regularly at horrendous injury reports.  Bill James My college prof called out to me: “Look at the numerical data, damn it.”

So I sat down and tabulated the number of serious injuries that have struck all teams in the LRS since the start of Spring Training.  For purposes of this analysis, I defined "serious injury" as any injury estimated by team trainers to last three weeks or longer.  Any injury estimated at 2-3 weeks would also be included; those 2 weeks or less (unlikely to prompt a DL stint) would not.

The results:

The average number of serious injuries per team was 5.4.  Only three teams suffered more than six serious injuries.  No team other than Ghosts had more than eight.  The Ghosts had twelve.

So my perception that the Ghosts have been the team most snake-bit by injuries is correct, right?  Wrong.

The fallacy of this analysis is that it measured only the number of serious injury incidents, but not the severity of those injuries.  In other words, a team with just, say, four serious injuries may have lost all four players for the year -- certainly a worse outcome than a string of twelve 3-6 week injuries.

With that in mind, I conducted a second analysis: I simply totaled the number of injury weeks suffered per team.  Any injury expected by trainers to last one week or longer was included.  Injuries lasting six days or fewer were excluded.  For injuries expected by the trainer to last a span of week – say, 3-4 – I counted the higher number.  This tally of weeks included the full amount of time the injury was expected to last even if that stretched into the offseason or, perhaps, next season.

The results:

Ah, perceptions.  The average number of weeks lost to injury per team was 62.  Viewed from this perspective, the Injury Gods have dumped more on two other SSG teams” Neo-Tokyo (121 weeks lost) and Kawaguchi (111).  This is due to some truly long-term injuries: NT lost two players for 12 and 13 months, while KAW lost three for 10, 10 and 4 months.  Fewer injury reports for those GMs to read, but more devastating.  Clearly, I have no reason to whine.  NII has been "lucky."

But of course, Bill James my college prof also talked about regression to the mean.  Or, for those teams hard hit, perhaps a progression to the mean.  Will the injury pendulum swing back for the Transmitters, Akira and Ghosts?  And would this balance out as the season goes on, or over the course of one or two more seasons?

We, and of course fans of those teams, will be watching.  Meanwhile, I have told the trainer to stay the hell out of my office.