Mat Latos is already a pretty good pitcher. You know the résumé: Young, throws hard, good strikeout rate, pretty good control, succeeded in a great pitcher's park in San Diego.
What the Cincinnati Reds are hoping, of course, is that they acquired a No. 1, an ace to front their rotation. Did they? Time will tell, but let's do a little study to see the pitchers Latos compares with. Via the awesomeness of the Baseball-Reference.com Play Index, I looked for pitchers in the past 20 years with the following attributes: (1) 23 years old; (2) thrown at 350 innings in the majors; (3) averaged at least 6.5 strikeout per nine innings; (4) had a strikeout-to-walk ratio of at least 1.75.
This gives us 21 pitchers including Latos, a pretty good comp list of young power pitchers who showed early success in the majors.
So, what happened to those guys after they entered their age-24 season? Since the Reds have control of Latos for the next four seasons, let's see how they did from ages 24 to 27 (or as many seasons as applicable). We'll rank the pitchers in order of ERA+ (ERA adjusted for park and league context, scaled to 100), with their average innings pitched per season over the applicable years in parenthesis.
1. Pedro Martinez, 173 ERA+ (226 innings)
2. Rich Harden, 140 (90)
3. Felix Hernandez, 137 (242)
4. CC Sabathia, 134 (221)
5. Matt Cain, 132 (221)
6. Jake Peavy, 127 (201)
7. Carlos Zambrano, 126 (211)
8. Tom Gordon, 110 (154)
9. Andy Benes, 103 (204)
10. Ramon Martinez, 101 (185)
11. Mark Prior, 101 (105)
12. Ismael Valdez, 99 (162)
13. Chad Billingsley, 98 (192)
14. Scott Kazmir, 89 (150)
15. Oliver Perez, 89 (137)
16. Dontrelle Willis, 88 (122)
17. Scott Olsen, 88 (115)
18. Jeremy Bonderman, 85 (107)
OK, not surprisingly, we see a range of outcomes, from success stories to guys who stagnated or regressed to guys who developed arm problems.
The biggest positive I see about Latos is he has the third-best SO/BB ratio on the list, behind Mark Prior and Brett Anderson. His strikeout rate is seventh, although two of those ahead of him are Oliver Perez and Scott Kazmir.
Latos' adjusted ERA through age 23 isn't that impressive, since he's been pitching in San Diego. However, it's worth noting that in his career he's pitched 244 innings on the road, 185 at home. He does have a better ERA at Petco (3.11 to 3.57), but his peripherals remain strong on the road.
It's also worth noting that Latos doesn't have a lot of wear on his arm. He only pitched 184 innings in the minor leagues, missing time in 2008 with a strained oblique and sore shoulder. He also began the 2011 season on the disabled list with an inflamed bursa sac in his right shoulder but only missed one start. While the minor shoulder issues certainly raise a red flag, there are no signs of extraneous workload like you can point to with Prior or Kazmir.
Latos' character and cockiness have been questioned in the past, but I'm not concerned about those issues; heck, Pedro Martinez wasn't exactly the most well-liked opponent either.
If there's a direct comparison to make, it could be two to other towering pitchers. Like Latos, Andy Benes stood 6-foot-6 and threw hard. He also came up with the Padres. Benes remained a solid pitcher (155 wins) but never took his game to the next level. So Reds fans can perhaps hope for the CC Sabathia career path. Through age 23, Sabathia had already pitched four seasons in the big leagues, with a 4.12 ERA. He improved his strikeout and walk rates at age 24, improved even more at age 25 and won a Cy Young Award at age 26.