The Rangers have always managed to put big fastball pitchers on the mound, the type who blow up radar guns and seduce scouts and fans. From Nolan Ryan to Bobby Witt to Mitch Williams to Robb Nen, Texas has never lacked in the big heat category.

But what Ryan was able to do that made him so uniquely, enduringly successful (and that often gets overlooked) was offset his triple-digit velocity with command of a hammer curve and Bugs Bunny changeup that prevented big league hitters from sitting on the heat.

Since Ryan retired, the organization had years of poor results developing pitchers able not only to miss bats with the fastball but to locate a breaking ball or change, as well. We're seeing it now with C.J. Wilson and Colby Lewis and Derek Holland (and occasionally Neftali Feliz) -- pitchers whose fastballs play up because of breaking balls that keep hitters honest at the least, if not completely off balance.

And there's a lot more of that coming.

What follows is one ranking of the top 10 secondary pitches (based primarily on future grades) among prospects in the Rangers farm system -- several of which could show up in Arlington before long.

1. TANNER SCHEPPERS, RHP, Oklahoma City: Curveball

The scariest thing about the idea that Scheppers has the most devastating breaking ball in the Rangers' system is that, outside of Feliz, the 23-year-old probably has the most dominant fastball, as well. The upper-90s velocity and hammer curve make him an obvious late-inning relief candidate, but the fact that he also locates a slider and change have the Rangers hopeful that his ultimate future lies in the rotation.

2. MARTIN PEREZ, LHP, Frisco: Change-up

At age 19, Perez is faring well against much older Double-A competition (3.34 ERA, 31 strikeouts in 29.2 innings), due in large part to a tumbling change that has made him even more effective against right-handed hitters than against lefties. Perez arrived in pro ball at age 16, wielding a fastball that scouts believed in and a curve that showed immediate promise, but his development of the change under the Rangers' tutelage has elevated him into the top tier of pitching prospects in all of baseball.

3. MATT THOMPSON, RHP, Hickory: Curveball

Thompson struggled with the transition from high school to pro ball after signing as the Rangers' seventh-round Draft pick in 2008, but the Burleson and Arlington product has developed quickly into one of the organization's top strike-throwers. His out pitch is a knee-buckling power curve with two-plane break. The 20-year-old improved to 4-1, 2.70 last night with a standout effort, holding Kannapolis to two runs on six hits and one walk, setting eight down on strikes and getting nine groundouts (with just two outs in the air). For the year, Thompson has racked up 38 strikeouts and just nine walks.

4. MARTIN PEREZ, LHP, Frisco: Curveball

Unlike Feliz and unlike Scheppers, Perez is unquestionably a starting pitcher, based largely on the fact that he has the makings of three plus pitches. While the changeup may be the more effective of his secondary offerings at the moment, it was the advanced feel he showed for his late-breaking curve that made him one of the highest-paid international free agents Texas had ever signed when they paid the Venezuelan native $580,000 in 2007.

5. DANNY GUTIERREZ, RHP, Extended Spring Training: Curveball

A true 12-to-6 hammer that buries itself on hitters, Gutierrez's curve promises to miss big league bats as long as the 23-year-old can get himself back on the mound after the latest of several off-field issues, this time a 50-game league suspension after testing positive for an ADHD medication that he failed to get a therapeutic use exemption for. Gutierrez, acquired last summer from Kansas City, touches the mid-90s with his fastball, but it's the curve that sets him apart.

6. MICHAEL KIRKMAN, LHP, Oklahoma City: Slider

A two-year struggle with his mechanics threatened to end Kirkman's career before it ever got untracked, but the durable left-hander put things back together in 2008 and took a huge step forward in 2009, earning a spot on the 40-man roster after the season. The 23-year-old locates a sharp slider to go along with low-to-mid-90s velocity, completely neutralizing left-handed hitters (.140/.245/.163). Despite a rash of walks in his last two starts, Kirkman stands at 4-1, 2.68 in eight Triple-A starts, striking out nearly a batter per inning and holding opponents to a .195 batting average.

7. JAKE BRIGHAM, RHP, Bakersfield: Curveball

Featuring a mid-90s fastball/power curve package and bulldog intensity, Brigham profiles as a potential eighth-inning weapon, though he needs to develop more consistency. The curve is a true out pitch when he locates it, with knee-buckling 12-to-6 action.

8. ROBBIE ERLIN, LHP, Hickory: Curveball

Erlin threw five perfect innings in his first career start on Tuesday, striking out nine of the 15 batters he faced. For the season, his numbers look like typos -- 25.1 innings, 11 hits, four walks, 31 strikeouts -- and his finest pitch is a sharp, two-plane curve. The 2009 third-rounder stands only six feet tall, but he's pitching as effectively as you could ever hope for out of a high school first-rounder and could move relatively quickly.

9. ALEXI OGANDO, RHP, Oklahoma City: Slider

Ogando's slider flashes plus potential though he gets inconsistent action on it. Refining the pitch might be the final step in the 26-year-old's apprenticeship. His upper-90s fastball and slider/change offerings were too much for the Texas League to handle (he posted a 1.15 ERA, .078 opponents' average, 21 strikeouts, and five walks in 15.2 innings for Frisco), and so far Triple-A hitters have managed only two singles and a double off him in four innings, striking out six times without drawing a walk. Chances are that we'll see Ogando in Arlington at some point this season, with the timetable dependent in part on the progress he makes with the breaking ball.

10. JOSH LUEKE, RHP, Hickory: Slider

The 25-year-old Lueke needs a promotion. In 17.2 South Atlantic League innings, he's scattered 12 hits and four unintentional walks while punching out a gaudy 33 hitters, many on a filthy slider that misses bats and induces ground balls at heavy rates when opponents manage to make contact. Lueke saw action at Bakersfield the last two seasons; it will be interesting to see whether Texas gives him a third run at Cal League hitters or if instead they challenge him with a two-level jump to Frisco to test his fastball-slider combination against more advanced hitters.