I posted about this in the "skipping Kendrick" thread, but I think it warrants its own thread. Tom Verducci, national baseball writer for SI, has come up with a "Year After Effect", also known as the Rule of 30, which indicates that young pitchers who throw more than 30 innings than their previous season tend to either get hurt or really struggle in the following season, or sometimes both. Here is an excerpt

Why can't they throw 200 innings? Simply put, they're not conditioned for it yet. It's like training for a marathon. You need to build stamina incrementally. The unofficial industry standard is that no young pitcher should throw more than 30 more innings than he did the previous season. It's a general rule of thumb, and one I've been tracking for about a decade. When teams violate the incremental safeguard, it's amazing how often they pay for it.

Pitchers generally feel the effects of abusive increases in workload the next year, not the season in which they were pushed. In other words, you might be able to finish that marathon for which you didn't properly train, but your body will have hell to pay for it. I call it the Year After Effect.

Here's the way I track it: Find major league pitchers 25-and-under who broke the 30-inning rule. In some cases a pitcher's innings the previous season may have been artificially depressed, such as by injury, so I'll use his professional high for the baseline, or, in the case of a recent draftee like Kennedy, his college workload. All innings count (minors, majors, postseason).

Link

Verducci highlights 7 pitchers in the danger zone for this season

Ian Kennedy
Fausto Carmona
Ubaldo Jiminez
Tom Gorzelanny
Dustin McGowan
Chad Gaudin
Yo Gallardo (boooo)

But the reason this is important is because of Cole Hamels. Hamels IP history, minors and majors, is

2003: 101.0 IP
2004: 16.0 IP
2005: 35.0 IP
2006: 181.1 IP (majors + minors)
2007: 190.2 IP

Hamels crashed through the barrier in 2006, and he ended up spending time on the DL last season with arm soreness, not a surprise. Of course, he has a checkered injury history, so this isn't the only factor at work. But Hamels still needs to be monitored, and he still needs to be kept around 200 IP total this season, including playoffs.

Kyle Kendrick

2005: 118.0 IP
2006: 176.0 IP (+58)
2007: 202.1 IP (+26, close to the danger zone, but wasn't hurt at all)

Kendrick seems to be lucky in that he wasn't injured last season, but the cumulative damage could be a problem.

Cole Hamels divided by zero and made the Rule of 30 disappear

Some more interesting examples

JA Happ

2002, NCAA: 51 IP
2003, NCAA: 83 IP (+32)
2004, NCAA + minors: 129.2 IP (+46)
2005, A+/A-: 78 IP
2006, A+/2A/3A: 160.2 IP (+82)
2007, 122 IP

Hmmm. Coincidence that he had arm trouble in 2005 after breaking the 30 inning barrier twice? Then the massive jump in 2006 and he again has arm trouble in 2007.

Andrew Carpenter

2006, 131.2 IP (college + minors)
2007, 163.0 IP (+32)

Carpenter is in the danger zone and should be monitored.

Carlos Carrasco

2004, 48.0 IP
2005, 83.0 IP (+35)
2006, 159.0 IP (+76)
2007, 140.0 IP

Did he struggle in Reading because of overuse the season before and he just wore down and started developing bad habits?

Pretty cool thread. What are the chances that the Phillies are aware of this?

Woody wrote:Pretty cool thread. What are the chances that the Phillies are aware of this?

2:1

Does Verducci get into physiology at all? The statistics here are at best only half the story. The emphasis on youth is relevant. Is there a difference between pitchers drafted out of high school and those out of college?

TenuredVulture wrote:Does Verducci get into physiology at all? The statistics here are at best only half the story. The emphasis on youth is relevant. Is there a difference between pitchers drafted out of high school and those out of college?

Innings are innings. The act of throwing a baseball is unnatural, and it doesnt matter if you're pitching to a high school senior or a 10 year MLB veteran. He's been tracking this for over 10 years, and the trend is very real. Its not an iron clad rule (which he mentions regarding Verlander), but it proves true many more times than not. You generally should not cross the 30 inning barrier.

Cool stuff. As an aside, is there any site that tracks pitches thrown during a year? I feel like there probably is for majors, but not for the minors. It has always seemed odd to me, because pitch count during a game is such a huge deal, but then it gets measure by innings over the year.

minorleaguebaseball doesnt track number of pitches, just gb:fb for each game. I kind of wish they did. Baseball Prospectus tracks number of pitches for major leaguers.

phuturephillies wrote:

TenuredVulture wrote:Does Verducci get into physiology at all? The statistics here are at best only half the story. The emphasis on youth is relevant. Is there a difference between pitchers drafted out of high school and those out of college?

Innings are innings. The act of throwing a baseball is unnatural, and it doesnt matter if you're pitching to a high school senior or a 10 year MLB veteran. He's been tracking this for over 10 years, and the trend is very real. Its not an iron clad rule (which he mentions regarding Verlander), but it proves true many more times than not. You generally should not cross the 30 inning barrier.

But I'm wondering if there isn't an absolute ceiling based on age. That regardless of what he did in 2007, a 21 year old pitcher should pitcher fewer than say 150 innings, a 22 year old pitcher should keep it under 175, etc.

Verlander may be a freak, but he was also 23 when he pitched those innings, not 20. If part of what is going on is that the body is still maturing in the early 20s, someone at 23 might not be subject to the same problems as someone at 20.

TenuredVulture wrote:

phuturephillies wrote:

TenuredVulture wrote:Does Verducci get into physiology at all? The statistics here are at best only half the story. The emphasis on youth is relevant. Is there a difference between pitchers drafted out of high school and those out of college?

Innings are innings. The act of throwing a baseball is unnatural, and it doesnt matter if you're pitching to a high school senior or a 10 year MLB veteran. He's been tracking this for over 10 years, and the trend is very real. Its not an iron clad rule (which he mentions regarding Verlander), but it proves true many more times than not. You generally should not cross the 30 inning barrier.

But I'm wondering if there isn't an absolute ceiling based on age. That regardless of what he did in 2007, a 21 year old pitcher should pitcher fewer than say 150 innings, a 22 year old pitcher should keep it under 175, etc.

I don't think you'll find any evidence of that. It may be true, but theres no evidence.

Essentially, Major League Baseball has made it easier to manage this and not break this limit by adding 1 year of control for teams over their minor leaguers. Prepsters must be added to the 40 man after 5 pro seasons, college kids after 4 seasons. If you draft a kid out of high school, you can easily stack his innings as such

Debut, GCL: 60 IP
2nd year, A-: 85 IP (piggybacking starters is the best solution)
3rd year, A+: 110 IP (use as a starter from April-June, use in relief for July/August)
4th year, AA: 130 IP (careful monitoring, allow them to get close to 140 IP)
5th year, 3A/MLB: 150 IP (use the pitcher as a starter in the minors from April to July, then use them in the bullpen in 3A and in the major league pen to finish the season.)

If you draft a kid out of high school and follow that approach, he's 22 in his 5th season and his arm has been taken care of.

Thinking more about this--Hamels has been extremely good thus far. If he keeps up even close to this level, it's going to be very, very, difficult to resist the temptation to over-use him according to these parameters.

And I suspect that an injury history means monitoring this is more critical than it would be otherwise. I guess we just hope that the NL East and wild card races are decided by mid-September.

The other night he wasn't used right. Pitch counts are still the #1 most important thing, and innings are 2nd, but they kind of go hand in hand. So many baseball teams are run inefficiently in terms of the composition of the roster, carrying too many pitchers, and the Phillies fall right in line. But then they choose to needlessly use Hamels in the 7th the other night, when he was at 92 pitches. Sure, the best case scenario is that he has an 8 pitch inning, but Hamels isn't that type of pitcher. Instead, he crossed the 105 barrier, which is not good. If you're going to carry 7 relievers, you need to use them. A 5 run lead, with 9 outs to go. There is ZERO justification for using Hamels there and adding another 20 pitches/1 inning onto his arm.

Hamels has had good results so far, but the way he's gotten them are worrisome. Too many fly balls, but even more worrisome not enough strikeouts and too many pitches thrown (indicating he's having difficulty inducing swings-and-misses).

I think he has a hard time throwing the changeup when its cold. That's based on nothing more than conjecture. Oh, and I really do disagree even more now that he's been used properly. Last year he averaged 99 pitches per start. This year, in 3 starts

103
103
111

I sense that Manuel is going to continue to do this. We need to pray that Gordon, Romero and Lidge are lights out and that Madson doesn't get hurt. Because if Charlie is afraid to call to the pen, we're in trouble, and Hamels is in trouble.

phuturephillies wrote:

TenuredVulture wrote:Does Verducci get into physiology at all? The statistics here are at best only half the story. The emphasis on youth is relevant. Is there a difference between pitchers drafted out of high school and those out of college?

Innings are innings. The act of throwing a baseball is unnatural, and it doesnt matter if you're pitching to a high school senior or a 10 year MLB veteran. He's been tracking this for over 10 years, and the trend is very real. Its not an iron clad rule (which he mentions regarding Verlander), but it proves true many more times than not. You generally should not cross the 30 inning barrier.

If "innings are innings" then shouldn't the relevant college and/or hs innings factor in here too? Maybe that arm has already thrown 100 innings in a season?

Part of my skepticism is any metric developed by Tom Verducci probably is not going to be "right" out of the box. But then again, jeff2sf hasn't invented any stats... yet.

How many pitches did Hamels average in his effective starts last year? His occasional clunker last year would tend to bring down his average, and he has yet to have a bad start this year.

phatj wrote:Hamels has had good results so far, but the way he's gotten them are worrisome. Too many fly balls, but even more worrisome not enough strikeouts and too many pitches thrown (indicating he's having difficulty inducing swings-and-misses).

I dunno if I'd be all that concerned. Even 3 games in, an ERA of .85 is going to involve getting pretty lucky. So, his ERA is likely to creep up as his luck evens out. Even if you point to fewer total strikeouts, I'd say that part of that is that over a certain number of innings, you can only get a finite number of outs. So, flyouts by definition will reduce the number of strikeouts.

If "innings are innings" then shouldn't the relevant college and/or hs innings factor in here too? Maybe that arm has already thrown 100 innings in a season?

He counts college innings in his totals.

Also of note, Hamels breakdown, by pitch type, through 3 starts

FB: 58%
CH: 31%
CV: 11%

I believe last year he was at 60-35-5.

phuturephillies wrote:

TenuredVulture wrote:Does Verducci get into physiology at all? The statistics here are at best only half the story. The emphasis on youth is relevant. Is there a difference between pitchers drafted out of high school and those out of college?

Innings are innings. The act of throwing a baseball is unnatural, and it doesnt matter if you're pitching to a high school senior or a 10 year MLB veteran. He's been tracking this for over 10 years, and the trend is very real. Its not an iron clad rule (which he mentions regarding Verlander), but it proves true many more times than not. You generally should not cross the 30 inning barrier.

I don't think this is true. Pitch count is a more sensible limit, although admittedly tougher data to get. I also believe that increasing the IP at a younger age is bound to cause more problems, because of the added problems of a developing arm. So, the increase in IP by Carrasco would be a particular concern, as would Hamels. Some sign of prior injury, as with Hmels and Happ also needs to be factored in and must cause more concern.

I am guessing that a low BB, low K, not super hard thrower like Kendrick may tolerate the added IP better than your average young pitcher. The added IP probably represent fewer additional pitches and the speed of the pitch is less.

Guys who throw a lot of wear-and-tear pitches like splitters and screwballs would also be expected to be more at risk.