Jordan Zimmermann signing a solid move despite decline in fastball velocity

By now, you have heard the news that the Tigers and free agent righthander Jordan Zimmermann have agreed to a deal that will bring him to Detroit. The former Washington Nationals starter has reportedly agreed to a contract worth five years and $110 million, which can be seen as somewhat of a bargain based on what many projections foresaw earlier this offseason.

Now that the Tigers have made a move for a front-end-to-middle-of-the-rotation-type starter, I believe that introductions are in order.

Jordan, meet fans. Fans meet Jordan.

Zimmermann has pitched for the Nationals his entire career, which has spanned parts of seven seasons. A survivor of Tommy John surgery, which he had in 2009, he has been a consistent performer primarily as the Nats' No. 2 guy -- that is, before Max Scherzer came in and bumped everyone down a notch. Zimmermann rarely walks anyone, and has thrown at least 195 innings in each of the last four seasons.

His last two seasons have been interesting. Following a career-best 5.3 WAR in 2014, Zimmermann regressed to 3.0 WAR in 2015, his lowest total since the injury-shortened 2010 season. Don't get me wrong, 2015 was still a darn good year. Getting three wins above replacement (WAR) out of a pitcher is solid production, and he would have been the second-best pitcher on the Tigers roster, behind Justin Verlander . However, there is still some concern for a pitcher who experienced that type of drop off heading into free agency.

Although he pitched at the end of 2010 after recovering from surgery, 2011 was Zimmermann's first full season as a part of the Nationals' rotation. Since the start of the 2011 season, his pitch usage has been relatively consistent.

Zimmermann has relied on his fastball approximately 64 percent of the time since 2011, a league average clip. He has not dipped below 60 percent in the past five seasons, but it's worth noting that he used it slightly more in 2014, throwing it over 70 percent of the time. That uptick in fastball usage coincided with a career-best season, and he dropped off one year later when his fastball usage went back to normal.

One of the reasons for Zimmermann's decline in 2015 could have to do with his dip in fastball velocity.

Jordan Zimmermann Pitches clocked 95.0 MPH/faster 2012 236 2013 272 2014 159 2015 31 94.0/faster 2012 883 2013 987 2014 928 2015 296

— Mark Simon (@msimonespn) November 29, 2015

Zimmermann's average four-seamer velocity dropped from 94.8 miles per hour in 2014 to 93.6 miles per hour last season, and he wasn't able to reach back and throw 95 miles per hour like he usually has in his career.

Last season was a year of adjustments for Zimmermann, and for the most part, he was able show that he can still pitch well with less velocity. Although he gave up more home runs in the second half of the season, his xFIP was better at 3.53 than it was in the first half at 4.05. His home run to fly ball ratio in the second half was 18.2 percent, but an inflated home run rate can sometimes be attributed to luck, especially for a guy who has historically been good at keeping the ball in the park. Plus, he upped his strikeout rate and lowered his WHIP in the second half. Aside from the inflated home run rate and ERA, Zimmermann's second half was reminiscent of his 2014 season.

Even if he doesn't fully regain his 2014 form, with an average salary of $22 million per year, more seasons like 2015 would easily make him worth the money.

Per Fangraphs, Jordan Zimermann's 2015 season was worth $23.8 mil. New deal with Tigers reportedly worth $110mil over 5 yrs ($22/per).

— Neil Greenberg (@ngreenberg) November 29, 2015

Because the Tigers locked him up on what appears to be a team friendly deal, Zimmermann doesn't have to pitch like his 2014 self to be worth the investment. No Tigers fans would mind if he were to rip off another five win season or two, but putting together more seasons in the 3.0-4.0 WAR range he has averaged since 2011 would be sufficient for what he is getting paid.

As it goes for players who experience career years in both the best and worst categories, Zimmermann's true value is probably somewhere in the middle of his 2014 and 2015 numbers. Given that he will be 34 at the end of his deal, there isn't a lot of risk for a significant drop off. If he duplicates his 2015 performance, the Tigers will still be paying him market value, or even slightly less than he is worth. If Zimmermann rebounds towards his career norms, then this deal will look like even more of a bargain. Either way, the surprise five-year signing looks like another smart move by rookie general manager Al Avila.