Two names featured prominently in yesterday’s trade rumordom were Gio Gonzalez and Jon Niese. Both expect to fetch a hefty price on the trade market as their teams, the A’s and Mets respectively, look for big returns on the cost-controlled lefties.

They are not identical pitchers but do share some similarities: above-average strikeout rates and good ground ball numbers. Gio racks up more Ks but also walks nearly twice as many hitters per nine innings than the young Mets hurler. Gio does a better job limiting home runs in an extreme pitchers park, though Citi Field is hardly a bandbox.

What do you get from these two pitchers? Let’s take a look.

The biggest difference, at this point in their careers, between Gonzalez and Niese is results. Gio Gonzalez has two 200+ inning seasons under his belt, each with an ERA under 4. That looks nice, as do all the strikeouts. The walks are scary but he seems to manage them well enough, thanks to his ability to miss bats and keep it in the park, with no small assist to the typically strong A’s defense supporting him.

Niese doesn’t have the big league innings of Gonzalez as the Mets brought him along slowly and he battled injury early in his career. A hamstring problem from 2009 carried over into 2010 then an oblique strain prematurely ended his 2011 campaign in August.

When he’s on the mound, Niese is a great “rate stats guy” but not the greatest “results guy.” Niese suffers as a ground ball guy playing in front of a very not-good defense. Is that the totality of his problems? I don’t think so. But he has the tools to be a top pitcher.

Jon Niese is one of only 16 pitchers with 300 innings pitched over the past two years who posted an above-average strikeout rate, issued fewer walks than average and induced more ground balls than the average big league starter. Other left-handed names on that list? CC Sabathia. David Price. Cole Hamels. Madison Bumgarner. Wandy Rodriquez. Jaime Garcia. That’s it. That’s a pretty good list, no?

So it is a matter of paying for potential versus paying for results. Both pitchers are still one season short of arbitration so there is plenty of cheap labor in their futures. How do they compare? Start with pitch repertoires.

Gio Gonzalez throws harder and his pitch data reflects it. He gets more swinging strikes on his four seam fastball, though Niese features a cutter. Gio’s curve is thrown harder as well though I like the look of Niese’s big, slow curve. Both Number 2′s miss their share of bats, around 12% for each pitcher.

They may miss a comparable number of bats but that doesn’t mean they have similar results. Using ESPN Stats & Info’s heat maps, we see a marked difference in the way hitters — specifically right-handed — handle their soft stuff.

Courtesy of ESPN Stats & Info

A massive gulf exists between the outcomes of these two pitchers off-speed pitches when they’re put into play. Though the overall wOBA isn’t too far off (.211 wOBA allowed for Gio, .289 for Niese) when you factor in swings and misses, the in-play values are much different. Gonzalez, pitching largely in Oakland, allowed just a .295 wOBA on balls in play while Jon Niese saw his rate soar to .402!

Any numbers of things may account for this difference. Gio Gonzalez could simply have better soft stuff, making good use of his changeup. The ballpark certainly plays a factor, as evidenced by the alarming number of warning track flies which fall on the happy side of the fence.

Without the benefit of hit f/x there is only so much we can speculate about Jon Niese’s very high in play average. Ground ball pitchers are sure to see more balls sneak through but his BABIP is second-highest among starters since 2010. Only John Lackey’s rate is higher in that time, and watching him struggle badly while pitching through injury this year suggests luck had very little to do with that number. Is Niese as bad as John Lackey was last year. No, no he is not. Something is still missing from the equation.

Projecting the development in these two pitchers comes back to a simple core belief: do you value the process or the results. Does Gio survive over the middle of the plate because he’s good or because he plays in a cavernous ballpark? Does Niese get hit hard because he telegraphs his curveball or because it flattens out too often? Can you teach control or does Gonzalez play with fire too often for your liking?

The choice for baseball’s general managers isn’t so cut and dried. Neither man comes cheap nor is either man likely to develop into a legit ace of a Major League staff. Two valuable pitchers who upgrade the rotation of whichever team willing to pony up the dough.

Information courtesy of Joe Lefkowitz, Fangraphs, and ESPN Stats & Info.