Decisions Decisions Decisions

A bunch of us were debating the “most valuable Expo of all time” on Twitter in response to this tweet

jonahkeri ‏@jonahkeri

Interesting debate if Vlad’s done. Who’s the best Expo of all-time, as in contributions only with Expos. Raines? Dawson? Carter? Vlad?

I mentioned Steve Rogers, winning pitcher in franchise history.  In going over his stats, I noticed something unusual.  In 1974, Rogers made 38 starts and received a decision in 37 of them.  (The one game in which he didn’t get the win or loss was a two-inning start on July 17 in which he left trailing and the Expos rallied to win.)

I wondered how rare it is for a pitcher to accrue a decision in every start of a season.  But first, a little historical context.  Here is a graph of the year-by-year % of pitcher starts that resulted in a decision, from 1918-2012:

From a high of 87.7% in 1918, there has been a relatively steady decline, bottoming out at 67.8% in 2008.  Through Monday, the 2012 percentage is 72.1%.  Reasons for this?  Well, starters are not going as deep into games as they used to, so there is a greater chance for a lead change and thus a no-decision.  And why are starters not going deep into games?  The birth of the seventh, eighth and ninth inning relief specialists, in concert with the introduction of the “save” in 1969, have changed the ways managers utilize their starters.  Here is the change in innings pitch per start over the past 50 years.

Now, let’s show both trends since 1961 on the same chart:

Though the absolute change in IP/start is greater than the change in Decision % (especially since 1987), the trends are relatively similar.

Let’s see the starting pitchers who were perfect in terms of “decision-making” in a season (minimum 30 starts with no relief appearances):

OK, so no full-time starter has made “perfect decisions” in 87 years.  What are the highest number of starts where a pitcher has had 100% decisions in recent history (again, no relief appearances in the season)?

And, for the sake of completeness, let’s look at the starting pitchers who were the champs of the “no-decision”.  These were the pitchers with the most starts without a decision in a year (no relief appearances):