What do the Twins do about Plouffe and Dozier? Extend? Go year to year? Hope to sell high at 30?

There has been some great discussion started by Seth on Dozier and Plouffe.

There also have been studies that show aging curves in the post steroid era are changing. Fewer players are maintaining their peak seasons into their thirties. There are many studies to read. Here is one by Jeff Zimmerman for Fangraphs.

I wondered how players currently around 33 years old have aged. With the help of play index from Baseball Reference, I searched for all players that had seasons with an OPS+ of 100 or better in 2006-7 as 26 or 27 year olds. There were many others that were below that level but they were probably not in any team consideration for getting an extension.

Before getting to the group there is one player in the group that should be addressed. One player by age 27 was with his 5th team having been waived twice and traded for the likes of Justin Huber and Robinson Diaz. After over 1500 plate appearances through age 27 he had an OPS+ of 89. For comparison, Chris Parmelee sits at 96 as the Twins have released him. Jose Bautista's performance since age 27 has been outstanding with his opportunity in Toronto. He didn't make the group because at age 27 Pittsburgh wasn't thinking extension, they were thinking dump.

I would like to place a table of data below so you can see all of the players. The new blogging software makes tables very difficult. All of the players in the search can be found in this google sheet.

For each player, I grouped their performance in 3 season chunks using ages 25-27, 28-30 and 31-33. I did this so that any single year variation did not stand out. I also used three as it is the norm in many projection systems.

There were a few middle infielders in the group including Mike Aviles, Khalil Greene, Brandon Phillips and Dan Uggla. There were some former Twins like Ryan Doumit, Justin Morneau and Jason Kubel. I added Jason Bartlett, but he did not fit the first criteria since his over 100 OPS+ seasons came after 27. His decline at 31-33 is similar to several others.

I wondered how many of the players would play have a better OPS+ from 31-33 as well as more plate appearances in that time frame. With over 20 players in the group, no one had more plate appearances and a better OPS+ from 31-33 than they did from 25-27. No one.

There were two players with a better OPS+ from 31-33. Matt Holliday had an increase of 5% in OPS+ while coming to the plate 5% less than he did from ages 25-27. Shane Victorino had an OPS+ increase of 4% while injuries and platooning dropped his playing time by 17%.

Brain Dozier through his age 27 season sits at a career OPS+ of 98 in 1670 career plate appearances. Maybe the Twins will get lucky and he will follow a path similar to Brandon Phillips. He only dropped 1% in his age 31-33 seasons while playing time dropped by 6%. From age 28-30, he was up 13% compared to 25-27.

Trevor Plouffe through age 28 has an OPS+ of 99.

Plouffe and Dozier started at an older age. Does that make a difference? Aging curve studies suggest that it will work against them and later career starts lead to earlier declines. There are several players in the group who started at age 25 or 26. They did not age well. The two that improved debuted at 22 (Victorino) and 24 (Holliday).

The decline of players into their early thirties is real. Teams need to plan for it as they make any extension offer. Player with and OPS+ of 125 or better over three years have plenty of room for decline. That isn't the case for Dozier and Plouffe. If the Twins do decide to buy free agent years from either, the Twins must be certain that there is something different in Plouffe and Dozier that will keep them playing at their peak longer than anyone in this group.