The Odds of That Expensive Free Agent Pitcher Staying Healthy

[Teflon]

What is a reasonable number of contract years to offer a free agent pitcher and what is the liklihood that any pitcher stays healthy for the length of that contract?  Ballclubs, just like actuaries at insurance companies, must have detailed data assessing the risks based on a pitchers' age, innings pitched and previous injury history.  Unfortunately, to take a shot at defining this risk for myself,  I'll have to make do with the less-than-detailed data I have available to me, at least until such time that the St. Louis Cardinals provide me with the passwords to the other MLB teams' databases,

 

I looked at all instances of starting pitchers, ages 25-33, making at least 30 starts in a season since 1998 (when the league expanded to its current number of teams) and then looked at the next 8 seasons for each of those pitchers to see how many time they failed to make 15 starts. To minimize the possibilities that they were merely ineffective and replaced, I also limited the group of pitchers to only those with sub 4.00 ERAs in those 30-start seasons. This left 475 pitchers' seasons to use as a basis.

 

The chart below shows the liklihood of those pitchers not making 15 starts in any subsequent season over the next 8 seasons. By the third season, for example, for a 29-year-old pitcher there is a 30% liklihood of having had a season of fewer than 15 starts. By the 5th season, it is around 45%.The biggest jumps in these probabilities actually occur between years 1 & 2 and years 2 & 3. By the time the pitcher has reached the 4-year mark, the increased risks grow more gradually - such that the liklihood of missing a season in a 5 year deal doesn't appear too much riskier than in a 6 or 7 year deal. 

 

It certainly would be enlightening (especially to agents) to see what big league clubs project the actual risk of a Darvish deal is over the long term.