1. Do Pitchers Try Harder for Their 20th Win?
Phil Birnbaum
July 31, 2009

2. Do pitchers try harder for their 20th win?
Bill James, "The Targeting Phenomenon"
Historically, there are more players who finished with one win than with two
More with 2 than with 3. More than 3 than with 4 …
Every number is harder to hit than the previous, except:
There are more pitchers with 20 wins than 19.

3. Do pitchers try harder for their 20th win?
Why?
Bill James: "players WANT to wind up the season hitting .250, rather than in the .240s. They tend to make it happen."
But HOW do they make it happen?

4. Do pitchers try harder for their 20th win?
Clutch pitching?
Do players actually try harder when they can win their 20th?
That would mean they wouldn't be trying their hardest in other games
Not a nice theory

5. Season win totals,

6. Maybe it should look more like this

7. Why? Five possible factors I could think of Take them one at a time
There could be more
Take them one at a time

8. Factor 1: extra starts
Maybe pitchers are given an extra start late in the season to try to get to 20
In that case, those pitchers would have a larger proportion of starts in September

9. Percentage of starts in September for pitchers who eventually finish with:
16 wins: 17.53%
17 wins: 17.77%
18 wins: 18.36%
19 wins: 18.49%
20 wins: 18.47%
21 wins: 18.15%
22 wins: 18.18%
-- A little bulge at 19-20, maybe 0.25%

10. Percentage of starts in September
The win pitchers had 9229 starts
An extra 0.25% means an extra 23 starts
Maybe 10 wins
By this analysis:
19-win pitchers, circumstances created 10 fewer (-10) of them
20-win pitchers, 10 extra (+10)

11. Factor 2: relief appearances
Maybe 19-win pitchers got a relief appearance to try to reach 20
Check the historical record
Big metaphorical wet kiss to Retrosheet

12. Factor 2: relief appearances
Eventual 20-game winners with relief wins:
1951: Early Wynn wins 18th
1951: Mike Garcia wins 19th
1956: Billy Hoeft wins 20th
1957: Jim Bunning wins 20th
1966: Chris Short wins 20th
1991: John Smiley gets 19th
1997: Randy Johnson gets 20th
7 extra wins

13. Factor 2: relief appearances
Eventual 19-game winners with relief wins: 3
Eventual 20-game winners with relief wins: 7 (previous slide)
Eventual 21-game winners with relief wins: 6
Take these numbers at face value, since they're exact historically

14. Factor 3: clutch pitching
The obvious question: did they just pitch better with 19 wins, with the 20th on the line?
How did the pitchers actually perform with various numbers of wins?

15. Team RA and win pct. for pitchers
17 wins: 3.72 RA, .658
18 wins: 3.54 RA, .652
19 wins: 3.54 RA, .655
20 wins: 3.62 RA, .615
21 wins: 3.53 RA, .676
22 wins: 3.34 RA, .774
(Note: RA is for team, not just the starter; wins are at the time of the start, not at end of season)
Only a tiny bit of difference – maybe .08 RA?
I feel better; pitchers are still team players

16. Team RA and win pct. for pitchers
Move the 20-win group from 3.62 to 3.54
Difference: 39 runs over 490 starts – 4 wins
Four 20-win pitchers "should have" moved to 21 wins
So four extra 20s, four fewer 21s

17. But wait!
The 20-win group's RA was only a bit higher than you'd expect …
But their winning percentage was much, much too low!
18 wins: 3.54 RA, .652
19 wins: 3.54 RA, .655
20 wins: 3.62 RA, .615
How come? Run support.

18. Factor 4: run support 19 wins: 3.54 RA, .655, 4.45 RS
Holy crap!
After achieving their 20th win, pitchers' batters let them down in their tries for 21
A huge 0.4 run per game shortfall!

19. Factor 4: run support
There were 490 starts by pitchers with exactly 20 wins
0.4 runs per game is 196 runs
That's 20 wins! Maybe 15 of those wins would have gone to the starter
So 15 pitchers got "stuck" at 20 wins instead of moving to 21
That's an extra 15 twenty-game winners, and 15 fewer twenty-one-game winners.

20. Factor 5: more decisions
Maybe when a pitcher is going for 20, the manager will leave him in longer
Looks like it! Wins per start, 17 to 22 wins:
.484, .496, .521, .463, .505, .554
Suppose they should have been That's 11 extra wins.
So we have an extra 11 twenty-game winners, and 11 fewer nineteen-game winners.

21. Totalling it up 19 –10 +3 –11 –18 20 +10 +7 +4 +15 +11 +47 21 +6 –4
Starts
Relief
Clutch
Support
Decisions
Total 19
–10 +3
–11
–18 20
+10 +7 +4
+15
+11
+47 21 +6 –4
–15
–13

22. One last adjustment
However: some of these pluses and minuses need to "move up" a category
Example: a manager gives his starter an extra relief appearance; he wins his 20th. But five days later, he wins his 21st.
We think that should be a move between 19 and 20, but it really wound up as a move between 20 and 21
I'm arbitrarily going to adjust
19s: from –18 to –16
20s: from +47 to +37
21s: from –13 to -7

23. Final score Final total:
19 game winners: –16
20 game winners: +37
21 game winners: –7
If we back all these effects out of the original data, there should be no more bulge at 20

24. Not perfect, but not bad

25. Summary
By this estimate, there were 37 "extra" 20-game winners compared to expected.
10 because of extra starts in September
7 because of relief appearances in September
3 because 20-game pitchers didn't pitch well enough to get to 21
11 because 20-game pitchers got such bad run support that they couldn't get to 21
6 because managers left the pitchers in longer in hopes they'd get their 20th that day.

26. Summary So is it because pitchers want it to happen?
No; it's mostly because managers want it to happen.
Broken down:
+23 manager decisions;
+3 pitchers pitching worse when already at 20;
+11 run support luck.

27. Reference
Bill James, "The Targeting Phenomenon," The Bill James Gold Mine 2008, p. 67