The Tigers have six good starting pitchers, if you believe that Drew Smyly should be able to transition back to starting after a successful pitstop in the bullpen. Steamer projects all five of their current starters for at least +3 WAR next year, and it’s not at all crazy to think that Smyly will be a +2 to +3 WAR pitcher as a starter, given his track record and stuff. The desire to move Smyly back into the rotation meant that had someone to go. For the last few months, the rumored trade candidates have been Rick Porcello and Max Scherzer.

Those guys can officially unpack their bags, however, as the Nationals have solved the Tigers pitching problem by relieving them of Doug Fister instead. And they did it at a shockingly low price, considering that Fister is one of the game’s most underrated pitchers. But let’s deal with what they gave up first.

According to Chris Cotillo, the trade is a 3-for-1, with the Nationals sending 22-year-old LHPs Robbie Ray and Ian Krol along with 25-year-old infielder Steve Lombardozzi to the Tigers in exchange for two years of Fister at arbitration prices. Ray is the primary piece of value here, as a young lefty with solid stuff who has already succeeded at Double-A, getting his walks under control for a 60 inning stint in the second half of the season. Combined with a velocity spike that saw him sitting in the low-to-mid 90s, Ray’s stock is up quite a bit from last year, and Baseball America just ranked him as the organization’s 5th best prospect heading into 2014, though his pronounced platoon splits and previous control issues suggest he might end up in the bullpen eventually.

Krol and Lombardozzi are filler pieces essentially. Krol’s a hard throwing youngster who fits best as a lefty specialist, and probably shouldn’t face good right-handers in critical situations at this point in his career. Lombardozzi’s a reserve infielder who isn’t much of a hitter and doesn’t have enough glove to cover shortstop, so while he’s young, the upside is pretty limited. Maybe he grows into his power and develops into an okay second baseman in a few years, but for right now, he’s kind of a replacement level bench guy without a ton of value.

So, in exchange for Fister, the Nationals surrendered a non-elite pitching prospect who has pitched a half season at Double-A and probably won’t rank in anyone’s Top 100 next spring, plus a couple of role players who might or might not end up amounting to anything. And in return, they’re getting two years of a very good starting pitcher at far below market prices. This trade is nothing short of a bonanza for the Nationals.

Seriously, look at where Fister stands relative to the game’s best pitchers over the last three years.

Those are the top 25 pitchers in baseball by RA9-WAR from 2011 to 2013. Note that Fister ranks 13th, two spots ahead of Scherzer. He ranks ahead of Zack Greinke, who got $150 million as a free agent last winter, and Anibal Sanchez, who got $85 million. He’s basically in a tie with Gio Gonzalez and Jordan Zimmermann, who have both finished in the top 10 in Cy Young voting over the last couple of years.

And that’s runs allowed, which penalizes Fister for having to pitch in front of the Tigers defense. By FIP-based WAR, Fister ranks 9th, right between David Price and Cole Hamels. This is not a case where out new fangled math has identified an undervalued pitcher who only looks good on FanGraphs and looks like crap by traditional metrics. By the things we value the most, Fister has been a top 10 pitcher in MLB over the last three years; by the things that MLB has traditionally valued, he’s been a top 15 pitcher over the same time frame.

The easy comparison here is James Shields. A year ago, the Rays decided that they couldn’t afford the final two arbitration payouts for Shields, and put their strike-throwing change-up specialist on the market. In the three seasons prior to 2013, Shields had thrown 680 innings with a 96/94/81 ERA-/FIP-/xFIP- line, putting up +10 WAR by either FIP or runs allowed based models. He’d been better in the two more recent years, though, putting up an 81/89/79 line in 477 innings. He was a durable innings eater who had been at times among the most dominant right-handed starters in the game.

James Shields landed the Rays a kid named Wil Myers, who was rated as the game’s third best prospect heading into the 2013 season, and ended up winning Rookie of the Year. I was one of many who thought (and still do think) the deal was a massive overpay for the Royals, so the Tigers shouldn’t have expected to land a Myers-style prospect for Fister, but you would think they could have gotten closer than this. Especially because Fister’s track record is even better than Shields’ was, as he’s put up +13 WAR over the last three years compared to Shields’ 10 WAR from 2010-2012. Even if you just go past two years and exclude Fister’s excellent 2011 season, he still grades out as very comparable to Shields’ final two seasons before last winter’s trade.

And yet, the Nationals gave up a good-not-great pitching prospect, a lefty reliever, and a bench guy. Realistically, this is not that different from the return they got by trading away Michael Morse last winter, when they landed A.J. Cole (now rated as their #2 prospect by BA, ahead of Ray), Blake Treinen (a fringy pitching prospect), and Krol, who is changing teams once again. A year ago, the Nationals flipped one year of an injury prone DH for this same kind of package of talent that is now netting them two years of one of the best starting pitchers in baseball.

This cost seems light even compared to other players traded with fewer years of team control on the books. Just this summer, the Rangers gave up four prospects of varying quality for Matt Garza, and it wouldn’t be hard to argue that C.J. Edwards is a prospect of similar value to Ray, and that the secondary pieces in that deal are also superior to what the Tigers just got for Fister. And that was for a half season of a worse pitcher, and the mid-season trade meant that the Rangers weren’t able to make Garza a qualifying offer. They paid a similar (or maybe higher) price for two months of Garza and no pick as to what the Nationals just paid for two years of Fister and the potential of a draft pick as compensation if he leaves after 2015.

It’s not like that deal was the crazy outlier here either. The Red Sox gave up Jose Iglesias for the right to pay Jake Peavy about $18 million over 1 1/2 years; Iglesias is probably a better return than the combination of talent Detroit just got for Fister, and Fister will make roughly $18 million over the next two full seasons. And again, Fister has been a lot better than Peavy.

We could keep running down the line all day. Two years of R.A. Dickey at $25 million cost the Blue Jays Travis D’Arnaud and Noah Syndergaard, both far better prospects than Robbie Ray. Fister isn’t coming off a Cy Young season, but he just threw 209 terrific innings, and then gave the Tigers two very good starts in the playoffs.

Maybe it’s the fact that Fister’s fastball sits at 89, or that he was a non-prospect for most of his days in the minor leagues, but barring an unknown injury that is about to wreck his value, it seems like 29 MLB teams are missing the boat on Doug Fister. If Fister were a free agent, he’d have been the best starter on the market by a good margin. This is a market where $50 million for Ricky Nolasco isn’t outrageous. As a free agent, I’d have expected Fister to land something in the range of what Anibal Sanchez got last winter. His market value is probably somewhere around $80 million for five years.

Instead, the Nationals will own his rights for the next two years at a grand total of less than $20 million, and the cost to acquire him was one decent pitching prospect and some filler. I don’t get it. Worse pitchers regularly cost far more, even with fewer years of team control. Are teams really still degrading pitchers based solely on fastball velocity, even after 800 innings of excellent Major League performance? Is there reason to think that Fister, at age-29, is about to magically stop pitching well?

I get that the Tigers had too many starters. I get that selling low on Porcello or giving up Scherzer while trying to contend might not be great ideas either. Maybe Robbie Ray is going to turn into an ace, and the Tigers will have turned two years of a good pitcher into six years of a good pitcher. It’s certainly within the realm of possibility, and if Ray develops into a quality starter, this trade should work out just fine for the Tigers.

But that still looks like a pretty big if, given what we know about the success rates of pitching prospects, especially non-elite pitching prospects with some legitimate question marks. It seems to me that two valuable seasons of one of the game’s best pitchers should be worth more than one decent but unspectacular pitching prospect. It seems to me that MLB teams have been paying much higher prices to acquire quality starting pitching, and that the Nationals just got a total steal.

Maybe the Tigers and the 28 other teams who decided not to make a better bid for Fister know something that I don’t. Maybe he really is about to suck, after four years of being consistently above average, and with no obvious warning signs in sight. Maybe he spent the off-season burning down orphanages in third world countries and we just haven’t heard about it yet.

Short of that, though, this just an outright robbery. In a market where the prices for mediocre pitchers are very high, the Nationals paid a moderate price for a very good pitcher. They might have had a disappointing 2013 season, but with Fister slotted in behind Strasburg, Gonzalez, and Zimermann, they’re going to be very tough to beat in 2014.