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Friday, January 27, 2012
Do relievers today perform better because they have shorter outings?
Dave is arguing that they do not:
On the other hand, strikeout rate has skyrocketed, increasing by 40% since 1982. This would seem to support the idea that relievers can be more effective in shorter stints, and that playing the match-ups can help prevent run scoring. However, there’s a problem with that theory – the strikeout rate of starting pitchers has gone up 41% during the same time frame. While strikeout rate has been raising at the same time that the modern bullpen has been evolving, this seems to be a case where correlation is not causation. If starters are seeing the same rise in strikeout rate, that points to a more fundamental shift among hitters – more sluggers swinging for the fences, the rise in acceptance of the strikeout as just another out among organizations – rather than a specific benefit being given to relievers from their new roles.
It would seem to me that this is evidence that they ARE performing better. While the number of starters per team has remained fairly stable (after all, you have 162 starts per team, and pretty much everyone is on a 5-man or 5-day rotation, and they average 100 pitches per start), the number of relievers have skyrocketed.
What happens when you give more jobs to guys on the bubble? Well, the overall average must go DOWN. If for example the average team in 1982 used 10 different relievers, and the average team in 2002 used 15 different relievers, then those five extra relievers would have been in AAA in 1982. The overall average in talent therefore would have gone down. But, we see the PERFORMANCE has remained relatively stable. This would imply that the good relievers must pitch better in shorter outings.
Let me try to illustrate numerically. I’ll just give some made-up numbers for talent:
Talent Reliever#
150 1
120 2
100 3
90 4
85 5
80 6
75 7
70 8
65 9
60 10
The average of the top 5 relievers on a team would be 109. But the average of the top 10 relievers on a team would be 89.
But, what if we add a new column that shows the performance level for each reliever, if we give them less to do:
Talent Reliever# Performance
150 1 170
120 2 140
100 3 120
90 4 110
85 5 105
80 6 100
75 7 95
70 8 90
65 9 85
60 10 80
Now, the performance level of the top 10 relievers is 109.
So, just as we know that the performance level of pitchers jumps substantially when pitching in relief than when pitching as a starter, it’s very possible that the performance level jumps somewhat when pitching in short relief than long relief.