Someone is going to trade for Jake Peavy. What type of pitcher are they going to get?

Peavy is a very good pitcher. He’s young – he won’t turn 28 until May 31 – and he’s under contract through the 2013 season. He also has an established track record of tremendous success. Sounds like a heck of a player, right?

Well, yes. But all of the above statements, while technically true, are also misleading. Let’s examine.

He’s young. This is, of course, true – 2009 will be Peavy’s age-28 season. However, he has thrown a lot of innings in his career already – 1261 to be precise, including at least 166 innings in each of the last six seasons. Additionally, Peavy is a rather significant injury risk. He had a strained elbow that caused him to miss some time this season, and remains an injury risk going forward.

So while Peavy is young, he’s also a rather large injury risk.

He’s under contract through the 2013 season. Yes, again, technically true. However, that contract isn’t exactly well-below market value.

Peavy is scheduled to make $8 million in 2009 – a very affordable sum, even for the most frugal of teams. However, in 2010 he will make $15 million, in 2011 he’ll make $16 million, in 2012 he’ll make $17 million, and there is a team option for 2013 worth $22 million (with a $4 million buyout). So while Peavy is indeed under contract through 2013, he will make $78 million in those five years. This is less than he could probably get on the open market, but $78 million is still a lot of money to commit to a pitcher.

He has an established track record of tremendous success. This is also true – and also misleading.

First of all, Peavy has pitched half of his games in PetCo Park, a notorious pitcher’s park. In his career, Peavy has a 2.77 ERA at home, but a 3.80 ERA on the road. The main reason for this is Peavy’s home-run rates.

At home, Peavy has allowed homers in 1.72% of his plate appearances. On the road, Peavy has allowed homers in 3.26% of his plate appearances. And we’re not talking small sample sizes here – remember, Peavy has pitched over 1200 innings in his career.

For those who like raw numbers rather than percentages, Peavy has given up 47 homers at home, and 81 homers on the road – even though he’s pitched 100 more innings at home than on the road.

Additionally his strikeout rate is better at home than on the road: 26.2% of plate appearances at home end in strikeouts, as compared to 21.7% on the road. His walk rate is also better at home: 7.1% at home, 8.5% on the road. I believe this could be due to Peavy being more confident about challenging hitters at home, because he knows that the ballpark will prevent homers. Therefore, he throws more strikes – which results in more strikeouts and fewer walks, while the spacious ballpark suppresses the homers he allows at home.

Finally, Peavy’s strikeout rate was noticeably down in 2008, and his walk rate was noticeably up. After striking out more than a batter per inning from 2004-2007, Peavy only struck out 8.6 batters per nine this year – and only 8.2 per nine after returning from his elbow injury. Additionally, he walked over three batters per nine this year, after never walking more than 2.87 per nine from 2004-2007.

Jake Peavy is still likely to be a very good pitcher in the future. However, PetCo Park helped his numbers tremendously – by suppressing his homers and allowing him to walk fewer and strike out more. Furthermore, his elbow woes should be of concern to whomever trades for him. Finally, his strikeout and walk rates – while still very good – are worse than in his last four seasons. All of these factors suggest that Jake Peavy is a rather significant risk, and any team that trades for him must take this into consideration and adjust their expectations accordingly.