Agent Scott Boras has the prize of free agency in Max Scherzer, and Boras has taken to touting his client’s “pitching odometer.”  Boras explained to Jon Heyman of CBS Sports, “[Scherzer] really has the [arm] of a 25 or 26 year old. This is like signing a 25 or 26-year-old pitcher.”

Perhaps reflecting what is found in Scherzer’s binder, Heyman cited the following stats:

“Did you know Scherzer, 30, has thrown 20,954 pitches, to 26,321 for Jon Lester and 29,461 for James Shields, the other top two free-agent pitchers in a top-heavy market containing three aces?”

Scherzer has thrown 8,507 fewer pitches than Shields and 5,367 fewer than Jon Lester. This difference may seem relevant, but in the end it will not matter. Instead, the focus should be on the trio’s birth date.

Context For Number Of Pitches Thrown

When looking at the total number of pitches, the zeros get in the way. For each game started, an ace will throw about 100 pitches. Most aces will start 30+ times a season, so each healthy ace-level pitcher can expect to throw at least 3,000 pitches in a season. The number could grow even higher with longer starts, more regular season starts and postseason games. Just using 3,000 pitches for a season and looking at each pitcher’s age, Boras’ difference can be explained by prorating the pitches thrown back to their age-29 season (Scherzer’s age at the end of last season).

Pitches prorated back to age-29 season
Scherzer: 20,954
Lester: 23,321
Shields: 17,461

The number of pitches thrown really just comes down to age. Scherzer’s arm had less mileage on it than Lester’s arm at the same age, but more than Shields. The difference of 8,500 pitches may seem like a ton, but for pitchers four years apart in age, the number is completely reasonable.

Pitches Thrown And Likelihood Of Next-Season DL Stint

Now, is there a magic number of pitches when a pitcher’s arm just quits being healthy? Is 25,000 pitches the point? 30,000? My study finds that no magic number exists. Actually, the opposite is true.

I looked at the career pitches thrown by pitchers from 2001 to 2012, then put the pitchers into 3,000-pitch groups and to find their chances of a DL stint next season. Here are the DL percentages for pitchers as they put more mileage on their arms.  (Note: 39% of all established pitchers will go on the DL at some point the next season.  (n) refers to the number of pitcher-seasons in the sample.)

# of pitches (n): DL rate, average # of DL days per pitcher
6000-8999 (674): 36%, 24
9000-11999 (470): 39%, 26
12000-14999 (324): 40%, 29
15000-17999 (225): 45%, 33
18000-20999 (179): 37%, 29
21000-23999 (111): 42%, 26
24000-26999 (99): 39%, 24
27000-29999 (88): 39%, 27
30000-32999 (71): 45%, 38
33000-35999 (47): 34%, 27
36000-38999 (28): 50%, 21
39000-41999 (26): 38%, 27
> 42000(79): 37%, 23

There are some increases and decreases, but generally the DL rate hovers around the expected 39%.

Here are the numbers grouped into 9,000-pitch blocks.

# of pitches (n): DL rate, average # of DL days per pitcher
6000-14999 (1468): 38%, 26
15000-23999 (515): 42%, 30
24000-32999 (258): 41%, 29
33000-41999 (101): 40%, 25
>42000 (79): 37%, 23

It may not seem intuitive that pitchers will have a smaller DL chance as they throw more, but they do. At 24,000 pitches, a pitcher has been productive and healthy enough to be in the league around eight seasons.  Besides just the number of DL stints, the time spent on the disabled list is just as important. The pitchers could go on the DL and stay there because of a major injury. If high-pitch pitchers were staying on the DL longer, the average number of days would be seen going up.  Instead, they decline.

Pitches Thrown And Expected Future Innings Pitched

The three pitchers in question — Scherzer, Lester, and Shields — are each looking for a multi-year deal. How many innings can teams expect out of these pitchers in the future? Looking at the pitches a pitcher has thrown in his MLB career from 2001 to 2009, here are the innings thrown in the next five seasons.

Pitches (n): IP
6000-8999: (468): 302
9000-11999: (364): 324
12000-14999: (249): 354
15000-17999: (176): 398
18000-20999: (129): 426
21000-23999 (86): 427
24000-26999 (81): 446
27000-29999 (68): 372
30000-32999 (45): 430
33000-35999 (32): 381
36000-38999 (17): 557
39000-41999 (18): 508
> 42000 (68): 476

And now the same data grouped into a few large groups.

Pitches (n): IP
6000-14999 (1081): 322
14000-23999 (391): 414
24000-32999 (194): 416
33000-41999 (67): 460
> 42000 (68): 750

Just because a pitcher has a ton of mileage on his arm doesn’t mean he is about to break down. He could continue to throw for years to come. The more pitches a pitcher has thrown, the better the chances he continues to throw. The three pitchers in question have passed the threshold of being healthy and good.

2015 DL Chances For Scherzer, Lester, Shields

Every pitcher (including these three) will eventually break down, we just don’t know when. An injury risk can be assigned to every pitcher. I have used a DL chance formula to determine the chance a pitcher will end up on the DL with accurate results. Using the formula, here their DL chances for 2015.

Name: Scherzer, Lester, Shields
Age: 29, 30, 33
GS (’12 to ’14): 98, 98, 101
DL Stints (’12 to ’14): 0, 0, 0
DL Chance: 34%, 35%, 38%

These three pitchers each have health (no recent DL stints) and a history of being able to make about 33 starts per season on their side. The only difference among them is age, which makes Scherzer the least likely to end up on the DL.

Boras continues to mention Scherzer’s pitching odometer as an advantage over Lester and Shields. However, the number of pitches thrown is not indicative of future injury. A high number shows the pitcher can hold up to the grind of being able to successfully throw for full seasons. The main issue between the three pitchers is age. Scherzer is four years younger than Shields. Scherzer’s body may still be able to hold up a bit better than the other pair, but they are still some of the healthiest pitchers in the league. The debate about the trio’s durability should begin and end with age.