Unlike my recent attempt to rank the 25 craftiest pitchers in baseball, it's a lot easier to quantify the best strikeout pitchers in the game. One statistic in particular, the K/9 rate (strikeouts per nine innings), will get us most of the way there.
That doesn't mean this will simply be a list of the 25 pitchers with the best K/9 rates in 2010, though. A couple other factors will also be at play.
First, there is the starter versus reliever question. We've seen enough pitchers transition from reliever to starter (and vice versa) over the years to know that it is a lot easier to maintain a high K/9 when you are pitching one inning at a time than when you have to conserve your stuff for the whole game.
Some pitchers defy that trend (see Morrow, Brandon), but generally speaking, pitching in relief allows for an extra two-to-three strikeouts per nine innings, something that will be factored into these rankings. It's also simply more impressive to maintain a high K rate over 200 innings than it is over 60 innings, so the list with be fairly starter-heavy.
Which brings me to the second factor: This list won't just consider 2010. While a pitcher won't get credit for a strikeout rate they haven't achieved since 2004, performances over the last three seasons (2008 to 2010) will be considered, as long as a pitcher hasn't seen a dramatic drop-off in strikeouts during that time.
Finally, while there will be no strict innings limit for inclusion on the list, pitchers with longer track records will generally be given preference over young pitchers who haven't yet proven that they can maintain a high K rate over the long haul.
But enough with the ground rules! Here are the 25 best strikeout pitchers in baseball today.
Jansen only has 27 innings on his major league resume so far, but he punched out 41 batters in those 27 innings. That's good for a 13.67 K/9, the third-highest rate of any pitcher who threw more than seven innings in 2010.
Those numbers are in line with his minor league numbers, too. Jansen had a K/9 of at least 14.00 at stops in Single-A and Double-A in 2009 and 2010.
It remains to be seen whether Kimbrel can beat out Johnny Venters for the closer role in Atlanta, but one thing is clear: This kid can strike people out.
Like Jansen, Kimbrel has only had a cup of coffee in the big leagues so far (20.2 innings), which explains why he's so far down the list despite a whopping 17.42 K/9 rate in 2010. That is far and away the best rate of any pitcher who threw more than two innings last year.
While it wouldn't be wise to expect him to remain quite that difficult to make contact off of, Kimbrel has put up impressive strikeout rates throughout his minor league career. He had K/9s ranging from 13.11 to 17.10 during stints at Single-A, Double-A and Triple-A in 2009 and 2010.
Bill James projects a 14.29 K/9 for Kimbrel in 2011.
The list of starting pitchers with a K/9 between 8.5 and 9.0 is a long one, but Lewis' 8.78 K/9 in 2010 just slightly edges out a pair of Rockies (Jorge De La Rosa and Jhoulys Chacin), a former reliever (Ryan Dempster), and a group of young upstarts (Jordan Zimmerman, Derek Holland, James McDonald and Jeremy Hellickson).
I owned Lewis from the very beginning of last season in my fantasy league, so I'll freely admit that he's a favorite of mine. He wasn't a big strikeout pitcher during his first go-around in the majors, but like the rest of his pitching skills, Lewis honed his strikeout ability during his stint in Japan and reemerged stateside as a new—and highly effective—pitcher.
While De La Rosa and Chacin just missed the cut, the Rockies' rotation isn't getting completely shut out here.
De La Rosa's 8.92 K/9 over more than 400 innings between 2008 and 2010 is actually significantly better than Jimenez's 8.23 mark during that period, but in a "what have you done for me lately" world, Jimenez distinguished himself with his 2010 performance.
De La Rosa has a great strikeout rate, but because he's never topped 200 innings, he's never registered a 200 strikeout season. Jimenez, on the other hand, was a workhorse in 2010, pitching 221.2 innings and finishing eighth in baseball with 214 strikeouts. Plus, Jimenez has continued to improve his strikeout rate, and his 8.69 K/9 in 2010 easily topped De La Rosa's 8.36.
Max Scherzer will strike batters out until he's blue in the face.
Scherzer has top 10 strikeout potential, and he could well find himself topping a list like this soon.
However, while Scherzer put up a 10.61 K/9 during his first 56 big league innings in 2008 and a very strong 9.19 K/9 in 2009, his strikeout rate slipped to 8.46 in 2010. That's still a very solid strikeout rate. It's just not anywhere near the top 10.
At just 26 years old, Scherzer, who had impressive strikeout rates throughout the minors, is still a very good bet to emerge as an elite strikeout pitcher this season.
Volquez proved during his 12 starts in 2010 that he was fully recovered from Tommy John surgery and could still strike batters out at an excellent clip. His 9.62 K/9 in 62.2 innings last year boosted his strikeout rate over three seasons with the Reds to a cool 9.33.
Those numbers are perfectly in line with Volquez's minor league strikeout totals, so if healthy, expect him to continue to mow down hitters at a similar rate in 2011.
Few saw the mustached man taking over for Trevor Hoffman as a dominating ninth-inning option for the Brew Crew, but that's exactly what happened in 2010.
Axford's facial hair and poise under late-inning pressure have drawn comparisons to Rollie Fingers, but at least when it comes to strikeout rate, Axford's 11.79 K/9 in 2010 blows Fingers' career mark of 6.9 out of the water.
Axford posted K/9s greater than 10.00 at every minor league stop in 2009 and 2010, so he should continue to punch out hitters at a rate Fingers could only dream of.
Hanrahan has had a fairly rocky tenure as a late-inning reliever with the Nationals and Pirates, but one thing he's always had going for him is the ability to be untouchable when he's on his game.
Hanrahan had very solid 9.92 and 10.13 K/9 rates in 2008 and 2009, respectively, and then upped the ante in 2010 with an impressive 12.92 K/9 rate. All of those numbers are well above Hanrahan's minor league rates, but considering that his strikeout rate has gradually increased in all four of his major league seasons, Hanrahan should continue to strike out plenty of batters in 2011.
You can make a strong case that Johnson has emerged as one of the league's 10 best starting pitchers, but he doesn't quite make that tier when it comes to strikeouts.
Johnson had a very nice 9.11 K/9 in 2010, but it was the first time he's surpassed a rate of 8.22. While his health was undoubtedly a big part of last season's success, Johnson still has some more work to do to prove he is truly an elite strikeout pitcher.
When it comes to strikeouts, Hamels' track record is quite similar to Johnson's.
Hamels put up a 9.10 K/9 in 2010, but it was just the second time in his career—and the first since his rookie season in 2006—that Hamels had a K/9 of more than 9.0. Like Johnson, Hamels has already clearly established that he's an excellent pitcher, but exactly how great a strikeout pitcher he is remains to be seen.
Norris has an opposite—and in the grand scheme of things, much bigger—challenge than Johnson and Hamels.
Norris has a 9.11 K/9 through his first 209 big league innings and has probably shown enough through his minor and major league career to establish himself as a guy who can strike out a batter per inning.
The question with Norris is whether he can develop his craft enough to become anything close to the overall pitcher that Johnson and Hamels are, a proposition that is very much in doubt.
You may think this is a bit low down on the list for a guy who led the majors in strikeouts in 2010, but there are two main reasons Weaver is situated here.
First, while durability and inning totals are definitely important factors, I consider K/9 rate to be an even bigger one. Weaver's 9.35 K/9 rate in 224.1 innings last year is incredibly impressive. But it's still important to remember that nine other starters made at least 12 starts and had a better strikeout rate than Weaver, and six starters made at least 26 starts with a better K/9 than he had.
The second—and more important—point is that Weaver still needs to prove that he can maintain such a high strikeout rate. Before last season, he had never posted a K/9 higher than 7.68.
Weaver's fastball barely touches 90 mph on the radar gun. So while it's possible he has developed into a crafty enough pitcher to strikeout a batter per inning without a nasty heater, the odds are against it.
Verlander's K/9 rate has fluctuated from 7.30 to 10.09 from 2008 to 2009, making last year's 8.79 rate just about in the middle.
Like Jimenez and Weaver, Verlander threw a lot of innings last year and finished near the top of the league in strikeouts. While it's unclear whether he can return to the 10.00-plus K/9 rate he put up in 2009, Verlander certainly has the stuff to get back there.
And even if he strikes out batters at a similar clip to last year, he's still one of the top 25 strikeout pitchers in baseball.
Hernandez finished just one strikeout behind Weaver, but he threw an additional 25 innings. Hernandez's strikeout rate is lower than most of the guys on this list, and you could argue that he should be a bit lower in the rankings.
But Hernandez has proven himself as a dominant workhorse and one of the surest bests for 200-plus strikeouts in baseball. Only Tim Lincecum, Justin Verlander and Jon Lester have more strikeouts than Hernandez over the last two seasons.
In addition to Hernandez, Dan Haren and Roy Halladay also deserve mention in this regard. Haren and especially Halladay had even lower K/9 rates than Hernandez in 2010, so they don't make the list. But like Hernandez, Haren and Halladay are proven performers who are good for 200-plus innings and 200-plus strikeouts every year.
Just call them Triple H.
Francisco posted a K/9 of at least 10.25 in each of the last three seasons in Texas, and his cumulative 10.89 rate is the ninth-best among all pitchers who have thrown at least 70 innings over that time span.
Francisco's track record of strikeouts is nearly identical to new teammate Octavio Dotel and likely White Sox closer Matt Thornton, who are each also worthy of mention here.
Latos burst onto the scene with a 9.21 K/9 rate in 2010, up from 6.93 during his first 50 major league innings in 2009.
Last year's strikeout rate is in line with his minor league numbers, and Latos' elite (11.8-plus) strikeout rates in the low minors suggest even bigger strikeout totals could be in store for him as he continues to develop.
Kershaw registered his first 200-plus strikeout season in 2010, but it was his second straight year with a K/9 rate of at least 9.34.
Like Latos, Kershaw had very high strikeout rates in the low minors, suggesting that he could soon be striking out even more batters at the major league level.
In 2010, Liriano regained the swagger and dominance he had prior to Tommy John surgery, and it showed up in his strikeout totals just like in the rest of his improved numbers.
Liriano, who had a 11.01 K/9 rate through his first 144.2 major league innings over 2005 and 2006, had not come close to that rate again until last season, when he posted a 9.44 K/9. If Liriano can stay healthy, it's possible he could again put up a K/9 of more than 10.00 sometime in the next couple of years.
Sanchez has put up a 9.43 K/9 over the last four seasons, including a 9.54 rate last year. His lowest K/9 during that time frame is 8.94.
Last season was Sanchez's first with 200-plus strikeouts, but with that level of consistency in his strikeout rate, there should be many more such seasons to come.
Broxton's 11.94 K/9 since 2008 is the third-highest among all pitchers that have pitched at least 70 innings over that time. During his six seasons in the major leagues, Broxton has never posted a K/9 lower than 10.54.
Another season like 2009, when he struck out 114 batters in just 76 innings, cannot be ruled out for Broxton.
Gallardo displayed nearly identical strikeout dominance in 2009 and 2010. In 2009, he struck out 204 batters in 185.2 innings; in 2010, it was 200 strikeouts in 185 innings. I'll save you the math: that's K/9 rates of 9.89 and 9.73, respectively.
Gallardo just turned 25 years old, and he struck out more than 12 batters per nine innings in AAA, so further growth in his strikeout rate is still possible.
In 2010, Morrow had an incredible K/9 rate of 10.95, by far the highest of any starting pitcher who threw more than 100 innings.
Morrow may well belong at No. 1 on this list, but he'll need to show that he can repeat a K/9 of more than 10.00 first—a number he only occasionally reached as a reliever from 2007 to 2009.
Among qualified starters over the last two seasons, only Tim Lincecum has a higher K/9 rate than Lester's 9.85 mark. Lester's 9.74 rate from last season is also second only to Lincecum.
Lester is coming off back-to-back seasons with 225 strikeouts, and given his strikeout rate and durability, he stands a good chance of reaching that mark for a third consecutive season.
Lincecum has had the highest strikeout rate among qualified starters in each of the last three seasons.
His K/9 topped 10.4 in 2008 and 2009, and even though it dropped to 9.79 last year, he was still the best strikeout pitcher among starters. Given his age and abilities, it would be surprising if Lincecum did not again top 260 strikeouts and a K/9 of 10.
Frankly, it is amazing that Lincecum isn't No. 1 on this list, but I just couldn't put him ahead of...
Yes, he's a relief pitcher, but Marmol's 2010 K/9 of 15.99 is simply ridiculous. In fact, it's the highest ever K/9 for a pitcher with 50-plus innings.
Marmol can't be expected to maintain that strikeout rate in 2011, and if he drops back down to the 11.00-12.00 K/9 he's put up in other years, Lincecum will overtake him on the list. But until that happens, Marmol has to be No. 1 with a 94 mph bullet.
He may not throw a single pitch in the major leagues in 2011, and almost certainly won't before the All-Star break. But once he returns from Tommy John surgery, Strasburg will shoot up this list in a hurry.
Although he only made 12 starts, Strasburg's 12.18 K/9 in 2010 was far and away the highest mark of any starting pitcher who threw 50-plus innings last year.
He probably won't be able to maintain quite that rate upon his return, but Strasburg is an even better bet than Morrow to eventually challenge Lincecum as the best strikeout pitcher among starters.