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What Does Ben Sheets' Forearm Tightness Mean for the 2009 Astros?

When things go bad for my team, my initial reaction is to immediately start looking toward what can be done for next season to ensure that whatever is currently going wrong doesn't. Right now, I'm thinking starting pitching big time. A few weeks ago, prior to our lightening hotness that was put out by Ike, Bud, et al., I polled you guys to see where you felt this team should head in the off-season. 16 of you said you wanted to target top tier FA pitching and 11 said they wanted free agent pitching, just not Sheets or CC.

A week ago, I couldn't have been more certain that the Astros were going to employ Ben Sheets as their #2 SP -- the stars were aligning just so. This week though, Ben Sheets' free agent pay day just took a HUGE hit. He left a game after 2 IP complaining of fore arm tightness -- a relatively benign area to complain about a tightness in were it something sudden. If it were something sudden, it could just be a cramp, or trying to put too much break on a ball. Something that some Gatorade and a few days off would cure easily. If it's something that has been lingering for awhile, then you have to start thinking flexor tendons and knifes. Sheets got honest with the media and claimed have been dealing with this problem for over a month, which has caused him to be up and down performance wise. As an Astros fan hoping for a run for October next year, it knocked the wind out of me.

But need we close the door on Sheets? What follows are a few attempts to quantify the Risk he presents and whether it should preclude us signing him this off-season.

NOTE: Before you vote, there's a whole lot more to the article that requires you clicking the link underneath the poll to read it.

Using preliminary data for Sheets' next season from Baseball Prospectus' PECOTA, Sheets is slated for 3.5 WARP in 149 IP. For those of you uninitiated in BPro terminology, think of that as reading: 3.5 Wins above Jack Cassel. Assuming for the sake of argument that he makes 160 IP, that makes him roughly worth about 4 WARP (3.969 for those who did the math). But how certain of his contributions can we be? Well, let's find out.

To start with his risk, I'm going to steal a table from the Hard Ball Times that gives us a pretty solid foundation to handicap Sheets for his propensity for injury.



That math on the chart is pretty simple. Impact is essentially measuring how missing time due injury or underperformance impacts the team given their depth at that position. Probability is the probability that the player under performs due to injury or whatever holds him back (attrition, altered mechanics, etc.).

To determine where Sheets falls on this spectrum, I'm going to borrow the method from the article which I got the chart from. I'm altering the methodology slightly because the impact scale is derived from the impact on the players success, which is inherent in my modeling, but I'm taking into account the depth of our rotation as well.


Probability: Very Low

Impact: Very High

Overall Risk: Medium

We've seen a lot Ben Sheets, so we know what he brings to the table. He's a high impact player, especially in a rotation that has the propensity to be weak for us next year. Over all his experience factor puts him at a medium risk. Which is a abstract way of saying he's either going to be on or off.

Skill Level:

Probability: Medium

Impact: Very High

Overall Risk: High

We know that Ben Sheets is very talented, but we also know he's either there or not there. Thus the probability here stems from his Experience and his impact and overall risk take into account that if he's not there, he leaves a huge hole in the Astros rotation.


Sheets was slated to have a strong chance at collapsing by PECOTA (35%), but he didn't. Instead he way over shot the system's prediction for a Break Out (2%) by nearing 200 IP and throwing absolutely dominantly (2.98 ERA). He had a 14% shot at Attrition, which I think has to be notched up for 2009, because the spike in IP and his untimely exit from the Brewers play off run leave a lot of question marks as to his health in 2009. In sum, Ben Sheets his going to be a high risk signing for any team, because the forearm tightness could be a very, very bad omen for 2009.

The thing to take into account in all of this is that Ben Sheets threw not just lot of innings, but a lot pitches this year. Why? Because Ned Yost felt that there was really no option but to let him go back out to the mound in late game situations, because the bull pen could not be trusted. He averaged 100 Pitches/Start, in comparison with Roy Oswalt who averaged 97 pitches a start, but in much more even manner. Sheets also made two Category 4 starts (Oswalt had none) which you can interpret as saying Ben Sheets had two starts which were just stupidly dangerous in terms of the number of pitches he threw. He would not face that kind of pressure in Houston -- at all.

Breaking down the abuse of Sheets further, we can look to another Baseball Prospectus proprietary tool, Pitcher Abuse Points. They work like this:

  • Take a pitchers pitch total from a game and subtract 100 (100 pitches, after much empirical analysis, was determined to be the tipping point to fatigue in pitchers -- therefore injury risk/abuse).
  • Take the remaining pitches and cube (x^3) them
Sheets, though averaging just 3 pitches more per start than Oswalt, has amassed 61,290 PAP (pitcher abuse points) . To date and in just 2 IP less, Roy has amassed a scant 21,000 by comparison. It's a ludicrous gap, which speaks to Ned Yost's utter abuse of Sheets and the fact that Sheets was not utilized intelligently by the Brewers this year.

It also begs the question: would Ben Sheets have fore-arm tightness if he only had 21,000 PAP? I don't think that he would. The research that has gone into PAP has yielded the finding that injuries are highly correlated with mounting levels of PAPs -- unless you're Tim Lincecum, Randy Johnson, or CC Sabathia (i.e. freaks). The deduction in this, is that Sheets is someone who can stay relatively healthy if he's not allowed to over exert himself on the mound all the time.


So what does this mean in terms of whether or not the Astros should look at sending $75 million and five years worth of a contract his way (possibly less at this point)? It means that it might not be that bad of a bet for us, if we handle him correctly (i.e. with kiddie gloves). Using the table above and the math from my analysis of his risk portfolio, Sheets walks away with an average score of 10 (5+15/2). This puts him in the lower range for high risk and I think that if handled appropriately, we can mitigate a lot of that risk simply by not letting him work too long. Thus, from a risk perspective, I'm going to call Ben Sheets a worthwhile FA signing -- something I thought I'd never do until I sat down to write this.

The question left to be answered -- and I'll do that next time (probably a week or two, I have to work out some math and methodology) -- is whether or not we'll get enough utility out of Ben Sheets to make him worth the dollar signs.