Detroit Tigers: Spencer Turnbull’s Trade Value

Spencer Turnbull could be the Detroit Tigers’ last big trade chip.

The concept of trading Spencer Turnbull isn’t particularly new. Just a few weeks ago our own Jake Boes wrote about Atlanta Braves fans clamoring for the big right-hander. But a recent tweet from erstwhile Detroit News columnist Lynn Henning stirred up the debate:

We know Lynn is never short on opinions. We also know he’s well connected with the Detroit Tigers front office, so perhaps his tweet was less speculation and more a reflection of what he’s heard from the organization. In any event, it probably merits a closer look.

Who Is Spencer Turnbull

To know if it’s worth trading Spencer Turnbull, we must first determine Spencer Turnbull’s worth. It’s difficult to pin down a player’s trade value without knowing how many potential suitors are out there, but we’ll do our best. Let’s start by looking at his results.

Spencer Turnbull’s Results

Spencer Turnbull’s traditional stats don’t look terribly enticing. There are 89 pitchers who have thrown at least 150 innings in the last two seasons, and in that time Turnbull owns a 4.47 ERA and an MLB-worst 5-19 record. But traditional stats can be misleading.

Turnbull has received just 2.9 runs of support per 9 innings pitched. He’s the only pitcher with fewer than 3 runs of support on average, and one of only two starters with fewer than 3.7 runs of support. Meanwhile, an elevated BABIP (.325) and low left-on-base percentage (68.9%) suggest more bad luck. As a result, his 3.92 FIP is half-a-run lower than his ERA.

Below you’ll see Turnbull’s results and how he compares to the other 88 pitchers in our sample.

To put that into words, Spencer Turnbull strikes out an average number of hitters, issues a well above-average number of walks, gets a lot of ground balls, and is elite at preventing home runs. He has been roughly average at run prevention, but is generally unlucky.

Let’s head to Baseball Savant to drill a bit deeper into Spencer Turnbull’s contact-based numbers. Below you’ll see where Turnbull ranks in terms of expected batting average (xBA), expected slugging percentage (xSLG), expected weighted on-base average (xwOBA), hard hit rate (95+), and average exit velocity (EV).

That’s a fairly average profile, save for the mildly alarming exit velocity. There aren’t any perfect comparisons for Turnbull out there, but we can generate a few comps. His Statcast batted ball data is similar to Aaron Nola’s, but Nola has significantly better command. Other comps could be Brad Keller with more strikeouts, Kyle Gibson without the homers, Padres-era Andrew Cashner, or the young version of Lance Lynn. Overall, Turnbull has performed like a low-end #3 starter or a solid #4. But it seems like there’s more in the tank.

Spencer Turnbull’s Stuff

It’s hard to define a pitcher’s stuff, but we may be able to get a solid estimate by looking at that group of 89 pitchers again and seeing where Turnbull ranks in terms of velocity, spin, movement, and pitch-specific results. Below you’ll see the results for each of Turnbull’s pitches. The numbers in the movement columns (Hmov, Vmov) are inches, and the Rank row indicates inches of movement compared to average for each offering.

Four-Seamer (out of 89)

Sinker (out of 38)

Sliders (out of 76)

Changeups (out of 87)

Curveballs (out of 82)

That’s a lot of data to comb through, but we can sum it up rather easily. All five of Spencer Turnbull’s pitches show at least above-average velocity and spin, and all but his four-seam fastball show above-average movement. It looks like the arsenal of a front-line power pitcher, but again, the results so far haven’t matched the stuff. Perhaps teams could see him as a candidate for an Astros-style conversion where he ditches his sinker and throws more breaking balls.

Spencer Turnbull’s Contract

Spencer Turnbull reached the majors late in 2018 and spent all of 2019 with the Tigers, so 2020 will be his second full year of service time. That means he won’t be a free agent for another four years, which is a huge selling point. We’ll make some adjustments at the end of this section, but for now we’ll project Turnbull to perform at roughly the same level over the next four seasons.

To Baseball Reference that’s worth about 10 Wins Above Replacement, while at FanGraphs it’s closer to 12 WAR, and at Baseball Prospectus it’s just 4 WARP. If we assume the cost of a win is roughly $8-10 million, then by the time he’s a free agent Spencer Turnbull will have been worth anywhere from $32 to $120 million. That’s a huge range, so let’s split the difference and say he’ll be worth 8 WAR at $9 million a win, or $72 million.

Turnbull is due about $580K next year, but then he’ll enter his arbitration years and start to get a bit more expensive. At roughly 2 WAR per year we would expect him to make about $3 million, $6.5 million, and $11 million in his three arbitration years, for total earnings of around $21 million. Subtract that from his $72 million in production and we’re looking at $50 million in surplus value.

Spencer Turnbull’s Issues

So $50 million in excess value is a nice, round number, but Turnbull has a few value-sapping warts. First, he turns 28 this year, and while that’s not excessively old, it may make a few teams wary. The second issue is his injury history. He’s never had major surgery, but he missed most of his 2016 season, and he’s made at least one trip to the IL every year since.

The final potential issue is his command. Turnbull’s 60.5% strike rate ranks 88th among those 89 pitchers with at least 150 innings in the last two seasons. Some teams undoubtedly consider him more of a reliever. These three issues throw more volatility into Turnbull’s future projection, and as such we should probably adjust his surplus value down to about $40 million.

Conclusion

The Tigers appear to be in possession of a $40 million asset with the stuff of a front-line starter, but the results of a back-end arm. Tomorrow we’ll look at the history of trading players like Spencer Turnbull and come up with a few potential landing spots for him.