Mike Napoli had a great two year run as a Texas Ranger, putting up quality offensive numbers and becoming a fan favorite. Napoli is now a free agent, and the Rangers really need a 1B/DH type. Jon Heyman's projections have Napoli getting a three year, $39 million deal as a free agent. That's the type of deal the Rangers could afford.
That said, I'd pass on Napoli at that price.
Let's look at Napoli over the past five seasons:
2011 was an outlier, but otherwise, pretty consistent, right? Yes, Napoli just turned 32, and ages 32-34 are going to be decline years, but he seems to be aging well.
Let's look at some other numbers, though:
This data comes from FanGraphs. As you can see, other than his fluky 2011 campaign, Napoli's ISO has been pretty steady. His HR/FB rate, however, dropped last year after being sky-high in 2011 and 2012, and high K rate has steadily climbed (save and except for the 2011 season).
Mike Napoli struck out a ton last year. Napoli's 187 strikeouts last season is tied for the 20th highest total in major league history. And Napoli put up that ridiculous total in just 587 plate appearances, leading to the 32.4% K rate.
The only qualified player in 2013 with a higher K-rate than Napoli was the Astros' Chris Carter. Other than Carter and Napoli, the only other players to strike out in at least 32% of their plate appearances in a season where they qualified for the batting title are Mark Reynolds (three times), Rob Deer (three times), Jack Cust (twice), Adam Dunn, Benji Gil, Dave Nicholson, and Jose Hernandez.
Napoli isn't swinging at more pitches lately -- his swing percentage of 41.5% last season was slightly higher than his swing rate when he was in Texas (40.3%), but lower than his career 42.0% swing rate. However, while Napoli has always had a lot of swing and miss in his game, his contact rate on balls both in the side and outside the zone have, per FanGraphs, dropped both in 2012 and 2013 from his 2011 levels, and in 2013, were both below his career averages (and significantly below the averages for the league as a whole). As a result, Napoli's contact rate last season was just 68%, the lowest it has been in his career, and the 6th lowest in MLB, behind Carter, Pedro Alvarez, Dan Uggla, Mark Reynolds, and Giancarlo Stanton.
So Napoli had a quality offensive season despite striking out at a historic rate while his HR/FB rate declined. How did he do it? With a .367 BABIP -- the 7th highest in the majors last season. His BABIP brought his overall numbers up to a level where he could record a 129 wRC+ -- a quality mark for a first baseman.
Here's the problem, though...if you are giving Napoli significant dollars over a three year deal, you aren't just assuming the risk that comes with the anticipated decline of a player in his early-30s, and you aren't just assuming the risk that he will be able to hold up, health-wise (and his health problems are what led to him getting just a one year deal last offseason).
You are also assuming that Napoli is either going to improve his K rate, or is going to maintain an elevated BABIP. If Napoli's BABIP returns to .310 -- what is has been historically -- you're getting an average first baseman/DH if everything else stays the same. And that K rate gives Napoli such a slim margin of error that, if it continues to go up, he starts becoming useless offensively.
So Napoli is a great story, and I wish him well wherever he goes...but I don't think he's going to be worth the big, multi-year deal he's going to get. And I'm hoping the Rangers pass on him if the price is 3/$39M, as Heyman suggests.